factor - a divisor of an integer n, also called a factor of n, is an integer m that may be multiplied by some integer to produce n.

1/2a-10b=c solve for a

1/2a-10b=c solve for a
Multiply each side of the equation by 2:
2/2a - 2(10)b = 2c
Simplify:
a - 20b = 2c
Add 20b to each side:
a - 20b + 20b = 2c + 20b
Cancel the 20b on the left side:
[B]a = 2c + 20b
[/B]
You can also factor out a 2 on the left side for another version of this answer:
[B]a = 2(c + 10b)[/B]

12!!!

This is a symbol for a triple factorial.
We have n!!! = n * (n - 3) * (n - 6) * ... * 1
Our subtraction of 3 never goes below one.
12!!! = [B]12 * 9 * 6 * 3
[MEDIA=youtube]xm2D7WxVjk8[/MEDIA]
[/B]

21 apples and 49 pears. What is the largest number of baskets to make and still use up all the fruit

21 apples and 49 pears. What is the largest number of baskets to make and still use up all the fruit
We use our [URL='https://www.mathcelebrity.com/gcflcm.php?num1=21&num2=49&num3=&pl=GCF+and+LCM']greatest common factor calculator for GCF(21, 49)[/URL] to get:
GCF(21, 49) = 7
This means with [B]7 baskets[/B]:
[LIST]
[*]We divide 21 apples by 7 to get 3 apples per basket
[*]We divide 49 pears by 7 to get 7 pears per basket
[/LIST]

24 coloring books, 60 crayons, and 84 markers can be packaged into at most how many identical packag

24 coloring books, 60 crayons, and 84 markers can be packaged into at most how many identical packages? How many of each would each package contain?
First, determine the greatest common factor (GCF) of 24, 60, and 84 using our [URL='http://www.mathcelebrity.com/gcflcm.php?num1=24&num2=60&num3=84&pl=GCF']GCF calculator[/URL].
GCF(24, 60, 84) = 12
So we have 12 identical packages.
Now, figure out how many coloring books, crayons, and markers for each package
[LIST]
[*]24/12 = 2 coloring books
[*]60/12 = 5 crayons
[*]84/12 = 7 markers
[/LIST]
[B]So we have 12 identical packages, each containing 2 coloring books, 5 crayons, and 7 markers[/B]

3 is a factor of 18 true or false

3 is a factor of 18 true or false
We go to our math engine and type in [URL='https://www.mathcelebrity.com/factoriz.php?num=18&pl=Show+Factorization']factors of 18[/URL] and we see that 3 is a factor of 18, so our answer is [B]TRUE.[/B]

32 girls and 52 boys were on an overseas learning trip . They were divided into as many groups as po

32 girls and 52 boys were on an overseas learning trip . They were divided into as many groups as possible where the number of groups of girls and the number of groups of boys is the same .how many boys and how many girls were in each group
We want a number such that our total members divided by this number equals our group size.
We take the greatest common factor (32,52) = 4
Therefore, we have:
[LIST]
[*][B]32/4 = 8 girls in each group[/B]
[*][B]52/4 = 13 boys in each group[/B]
[/LIST]

5 books and 5 bags cost $175. What is the cost of 2 books and 2 bags

5 books and 5 bags cost $175. What is the cost of 2 books and 2 bags
Let the cost of each book be b and the cost of each bag be c. We're given
5b + 5c = 175
We can factor this as:
5(b + c) = 175
Divide each side of the equation by 5, we get:
(b + c) = 35
The problem asks for 2b + 2c
Factor out 2:
2(b + c)
we know from above that (b + c) = 35, so we substitute:
2(35)
[B]70[/B]

A adalah faktor dari 36 tetapi bukan kelipatan dari 4. Tentukan nilai a sebesar yang mungkin!

A adalah faktor dari 36 tetapi bukan kelipatan dari 4. Tentukan nilai a sebesar yang mungkin!
[URL='https://www.mathcelebrity.com/factoriz.php?num=36&pl=Show+Factorization']Kami memasukkan faktor 36 ke dalam enjin carian kami dan kami [/URL]mendapat:
{1, 2, 3, 4, 6, 9, 12, 18, 36}
Menyaring nombor yang bukan faktor 4, kami mendapat:
[B]A = {3, 6, 9, 18}[/B]

A bag contains 3 black, 4 red, 3 yellow, and 2 green marbles. What is the probability of drawing a b

A bag contains 3 black, 4 red, 3 yellow, and 2 green marbles. What is the probability of drawing a black and then a red marble out of the bag without replacing the black marble before drawing the red marble?
The phrase [U][B]without replacement[/B][/U] is a huge clue on this problem.
Take each draw and calculate the probability.
Draw 1: P(Drawing a red)
P(Drawing a red) = Total Red marbles n the jar / Total marbles in the jar
P(Drawing a red) = 4/12
4/12 simplifies to 1/3 using a common factor of 4:
P(Drawing a red) = 1/3
Draw 2: P(Drawing a black)
P(Drawing a black) = Total Black marbles in the jar / Total marbles in the jar
[I]We drew one red marble already. Without replacement means we do not put it back. Therefore, we have 12 - 1 = 11 marbles left in the jar.[/I]
P(Drawing a black) = 3/11
The question asks, what is the the following probability:
P(Drawing a Red, Drawing a Black)
Because each draw is [I][U]independent[/U], [/I]we multiply each draw probability together:
P(Drawing a Red, Black) = P(Drawing a Red) * P(Drawing a Black)
P(Drawing a Red, Black) = 1/3 * 3/11
P(Drawing a Red, Black) = [B]1/11[/B]

A box is filled with 5 blue cards,2 red cards, and 5 yellow cards. A card is chosen at random from t

A box is filled with 5 blue cards,2 red cards, and 5 yellow cards. A card is chosen at random from the box. What is the probability that it is a blue or a yellow card? Write your answer as a fraction in simplest form.
We want P(B) + P(Y)
P(B) = 5/12
P(Y) = 5/12
P(B) + P(Y) = 5/12 + 5/12 = 10/12
Reduce this fraction using 2 as our common factor:
[B]5/6[/B]

A computer randomly generates a whole number from 1 to 25. Find the probability that the computer ge

A computer randomly generates a whole number from 1 to 25. Find the probability that the computer generates a multiple of 5
[URL='https://www.mathcelebrity.com/factoriz.php?num=25&pl=Show+Factorization']Multiples of 5[/URL]:
{1, 5, 25}
So we have the probability of a random number multiple of 5 is
[B]3/25[/B]

A desk drawer contains 10 blue pencils, 7 red pencils, and 8 green pencils. Without looking, you dra

A desk drawer contains 10 blue pencils, 7 red pencils, and 8 green pencils. Without looking, you draw out a pencil and then draw out a second pencil without returning the first pencil. What is the probability that the first pencil and the second pencil are both green?
We are drawing without replacement. Take each draw probability:
[LIST=1]
[*]First draw, we have a total of 10 + 7 + 8 = 25 pencils to choose from. P(Green) = 8/25
[*]Next draw, we only have 24 total pencils, and 7 green pencils since we do not replace. Therefore, we have P(Green)= 7/24
[/LIST]
Since both events are independent, we have:
P(Green) * P(Green) = 8/25 * 7/24
P(Green) * P(Green) = 56/600
Using our [URL='http://www.mathcelebrity.com/gcflcm.php?num1=56&num2=600&num3=&pl=GCF']GCF Calculator[/URL], we see the greatest common factor of 56 and 600 is 8. So we divide top and bottom of the fraction by 8.
[B]P(Green) * P(Green) = 7/75[/B]

A factory put cakes into boxes of 6 how many boxes can they fill with 3285

A factory put cakes into boxes of 6 how many boxes can they fill with 3285
3285 cakes / 6 cakes per box = [B]547.5 boxes[/B]

A farmer was 1/3 of his land to grow corn, a quarter of his land to grow lettuce, and 12.5% of his l

A farmer was 1/3 of his land to grow corn, a quarter of his land to grow lettuce, and 12.5% of his land to grow green beans. He uses the remaining 7 acres to grow wheat.How many total acres does the farmer own?
Convert all land portions to fractions or decimals. We will do fractions:
[LIST]
[*]1/3 for corn
[*][I]A quarter[/I] means 1/4 for lettuce
[*]12.5% is 12.5/100 or 1/8 for green beans
[/LIST]
Now add all these up:
1/3 + 1/4 + 1/8
We need a common factor for 3, 4, and 8. Using our [URL='https://www.mathcelebrity.com/gcflcm.php?num1=3&num2=4&num3=8&pl=LCM']LCM Calculator[/URL], we get 24.
1/3 = 8/24
1/4 = 6/24
18 = 3/24
Add them all up:
(8 + 6 + 3)/24
17/24
This means 17/24 of the land is used for everything but wheat. Wheat occupies (24-17)/24 = 7/24 of the land.
We'll use a for the number of acres on the farm.
7a/24 = 7
[B]a = 24[/B]

A is the set of factors of 12

A is the set of factors of 12
Type in [URL='https://www.mathcelebrity.com/factoriz.php?num=12&pl=Show+Factorization']factor 12[/URL] into our math engine and we get:
A = {[B]1, 2, 3, 4, 6, 12[/B]}

A mother duck lines her 13 ducklings up behind her. In how many ways can the ducklings line up

A mother duck lines her 13 ducklings up behind her. In how many ways can the ducklings line up?
In position one, we can have any of the 13 ducks.
In position two, we can have 12 ducks, since one has to occupy position one.
We subtract 1 each time until we fill up all 13 positions.
We have:
13 * 12 * 11 * ... * 2 * 1
Or, 13!. [URL='https://www.mathcelebrity.com/factorial.php?num=13!&pl=Calculate+factorial']Typing 13! into our search engine[/URL], we get [B]6,227,020,800[/B] ways the ducklings can line up behind the mother duck.

A natural number greater than 1 has only itself and 1 as factors is called

A natural number greater than 1 has only itself and 1 as factors is called a [B]prime number.[/B]

A pair of numbers has an HCF (Highest Common Factor) of 3, and an LCM (Lowest Common Multiple) of

A pair of numbers has an HCF (Highest Common Factor) of 3, and an LCM (Lowest Common Multiple) of 45 . If one of the numbers in the pair is 15 , what is the other number?
[LIST=1]
[*]Prime Factorization for 15 is 3 * 5
[*]Prime Factorization for 9 is 3 * 3
[*]LCM of (9, 15) = 35
[/LIST]
[URL='https://www.mathcelebrity.com/gcflcm.php?num1=9&num2=15&num3=&pl=GCF+and+LCM']Check out this link here to see the details[/URL]

A pretzel factory has daily fixed costs of $1100. In addition, it costs 70 cents to produce each bag

A pretzel factory has daily fixed costs of $1100. In addition, it costs 70 cents to produce each bag of pretzels. A bag of pretzels sells for $1.80.
[U]Build the cost function C(b) where b is the number of bags of pretzels:[/U]
C(b) = Cost per bag * b + Fixed Costs
C(b) = 0.70b + 1100
[U]Build the revenue function R(b) where b is the number of bags of pretzels:[/U]
R(b) = Sale price * b
R(b) = 1.80b
[U]Build the revenue function P(b) where b is the number of bags of pretzels:[/U]
P(b) = Revenue - Cost
P(b) = R(b) - C(b)
P(b) = 1.80b - (0.70b + 1100)
P(b) = 1.80b = 0.70b - 1100
P(b) = 1.10b - 1100

A square of an integer is the integer. Find the integer.

A square of an integer is the integer. Find the integer.
Let the integer be n. The square means we raise n to the power of 2, so we have:
n^2 = n
Subtract n from each side:
n^2 - n = n - n
n^2 - n = 0
Factoring this, we get:
n(n - 1) = 0
So n is either [B]0 or 1[/B].

A student and the marine biologist are together at t = 0. The student ascends more slowly than the m

A student and the marine biologist are together at t = 0. The student ascends more slowly than the marine biologist. Write an equation of a function that could represent the student's ascent. Please keep in mind the slope for the marine biologist is 12.
Slope means rise over run.
In this case, rise is the ascent distance and run is the time.
12 = 12/1, so for each second of time, the marine biologist ascends 12 units of distance
If the student ascends slower, than the total distance gets reduced by an unknown factor, let's call it c. So we have the student's ascent function as:
[B]y(t) = 12t - c[/B]

A tourist in Ireland wants to visit six different cities. How many different routes are possible?

A tourist in Ireland wants to visit six different cities. How many different routes are possible?
[URL='https://www.mathcelebrity.com/factorial.php?num=6!&pl=Calculate+factorial']We want 6![/URL] which is [B]720[/B]

A toy company makes "Teddy Bears". The company spends $1500 for factory expenses plus $8 per bear. T

A toy company makes "Teddy Bears". The company spends $1500 for factory expenses plus $8 per bear. The company sells each bear for $12.00 each. How many bears must this company sell in order to break even?
[U]Set up the cost function C(b) where b is the number of bears:[/U]
C(b) = Cost per bear * b + factory expenses
C(b) = 8b + 1500
[U]Set up the revenue function R(b) where b is the number of bears:[/U]
R(b) = Sale Price per bear * b
R(b) = 12b
[U]Break-even is where cost equals revenue, so we set C(b) equal to R(b) and solve for b:[/U]
C(b) = R(b)
8b + 1500 = 12b
To solve for b, we [URL='https://www.mathcelebrity.com/1unk.php?num=8b%2B1500%3D12b&pl=Solve']type this equation into our search engine[/URL] and we get:
b = [B]375[/B]

A toy factory makes 5,000 teddy bears per day. The supervisor randomly selects 10 teddy bears from a

A toy factory makes 5,000 teddy bears per day. The supervisor randomly selects 10 teddy bears from all 5,000 teddy bears and uses this sample to estimate the mean weight of teddy bears and the sample standard deviation. How many degrees of freedom are there in the estimate of the standard deviation?
DF = n - 1
DF = 10 - 1
[B]DF = 9[/B]

A vendor sells h hot dogs and s sodas. If a hot dog costs twice as much as a soda, and if the vendor

A vendor sells h hot dogs and s sodas. If a hot dog costs twice as much as a soda, and if the vendor takes in a total of d dollars, how many cents does a soda cost?
Let the cost of the soda be p. So the cost of a hot dog is 2p.
The total cost of hot dogs:
2hp
The total cost of sodas:
ps
The total cost of both equals d. So we set the total cost of hots dogs plus sodas equal to d:
2hp + ps = d
We want to know the cost of a soda (p). So we have a literal equation. We factor out p from the left side:
p(2h + s) = d
Divide each side of the equation by (2h + s)
p(2h + s)/(2h + s) = d/(2h + s)
Cancel the (2h + s) on the left side, we get:
p = [B]d/(2h + s[/B])

Alex says all factors of 16 are even why is she wrong

Alex says all factors of 16 are even why is she wrong.
[URL='https://www.mathcelebrity.com/factoriz.php?num=16&pl=Show+Factorization']Type in factor 16[/URL] into our search engine. We get the following factor of 16:
1, 2, 4, 8, 16
[B]All of these are even [I]except[/I] 1, which is odd. This is why Alex is wrong.[/B]

Alice is a machinist in a shirt factory. For the first 180 shirts she is paid $2.20 and then $2.90 p

Alice is a machinist in a shirt factory. For the first 180 shirts she is paid $2.20 and then $2.90 per garment thereafter. What are her gross wages for a week in which she produces 240 shirts?
Calculate commission on the first 180 shirts (Commission 1):
Commission 1 = Shirts (up to 180) * $2.20
Commission 1 = 180 * $2.20
Commission 1 = $396
Calculate commission on the rest of the shirts about 180 (Commission 2):
Commission 2 = Shirts Above 180 * $2.90
Commission 2 = (240 - 180) * $2.90
Commission 2 = 60 * $2.90
Commission 2 = $174
Calculate Total Commission:
Total Commission = Commission 1 + Commission 2
Total Commission = $396 + $174
Total Commission = [B]$570[/B]

Ana has 24 carrots, 12 cucumbers, and 36 radishes. She wants to make identical vegetable baskets usi

Ana has 24 carrots, 12 cucumbers, and 36 radishes. She wants to make identical vegetable baskets using all of the vegetables. What is the greatest number of baskets she can make
The key to solving this problem is asking what is the common factor between the 3 numbers. We want the greatest common factor or GCF
[URL='https://www.mathcelebrity.com/gcflcm.php?num1=12&num2=24&num3=36&pl=GCF']GCF(12, 24, 36) [/URL]= [B]12[/B]
We divide up our 12 baskets into carrots, cucumbers, and radishes. Each basket of the 12 baskets has the following:
[LIST=1]
[*]12 cucumbers / GCF of 12 = [B]1 cucumber per basket[/B]
[*]24 carrots / GCF of 12 = [B]2 carrots per basket[/B]
[*]36 radishes / GCF of 12 = [B]3 radishes per basket[/B]
[/LIST]
[B][MEDIA=youtube]D1KTOP0h2P4[/MEDIA][/B]

At a light bulb factory 4 out of every 25 light bulbs are defective. How many light bulbs would you

At a light bulb factory 4 out of every 25 light bulbs are defective. How many light bulbs would you excpect to be defective out of 350 light bulbs
Set up a proportion of light bulbs to defects where d is the number of defects per 350 light bulbs:
4/25 = b/350
[URL='https://www.mathcelebrity.com/prop.php?num1=4&num2=b&den1=25&den2=350&propsign=%3D&pl=Calculate+missing+proportion+value']Type this proportion into our search engine[/URL], and we get:
b = [B]56[/B]

ax + b = cx - d

We are solving for x:
Subtract b from each side:
ax = cx - d - b
Subtract cx from each side:
ax - cx = -d - b
Factor out x from the left side:
x(a - c) = -d - b
Divide each side by (a - c)
x = (-d - b)/(a - c)

ax - mn = mn + bx for x

ax - mn = mn + bx for x
Add mn to each side:
ax - mn + mn = mn + bx + mn
Cancel the mn terms on the left side and we get:
ax = bx + 2mn
Subtract bx from each side:
ax - bx = bx - bx + 2mn
Cancel the bx terms on the right side:
ax - bx = 2mn
Factor out x on the left side:
x (a - b) = 2mn
Divide each side of the equation by (a - b):
x (a - b)/(a - b) = 2mn/(a - b)
Cancel the (a - b) on the left side and we get:
x = [B]2mn/(a - b)[/B]

Besides 8 and 1, what is one factor of 8

Besides 8 and 1, what is one factor of 8.
Using our [URL='http://www.mathcelebrity.com/factoriz.php?num=8&pl=Show+Factorization']factor calculator[/URL], or entering the shortcut [B]Factor 8[/B], we get the following factors:
1, 2, 4, 8
Excluding 1 and 8, we have [B]2, 4[/B]

Binomial Distribution

Free Binomial Distribution Calculator - Calculates the probability of 3 separate events that follow a binomial distribution. It calculates the probability of exactly k successes, no more than k successes, and greater than k successes as well as the mean, variance, standard deviation, skewness and kurtosis.

Also calculates the normal approximation to the binomial distribution with and without the continuity correction factor

Calculates moment number t using the moment generating function

Also calculates the normal approximation to the binomial distribution with and without the continuity correction factor

Calculates moment number t using the moment generating function

Bob has 4/5 of a pound of fudge. He wants to share it with Sue. How much of a pound of fudge will bo

Bob has 4/5 of a pound of fudge. He wants to share it with Sue. How much of a pound of fudge will both of them get?
If Bob shares the fudge with Sue, we assume they split equal parts. This means:
We take 4/5 total and divide into 2 for 2 people:
4/5/2
This is the same as 4/5 * 1/2
4/10
This fraction is not simplified.
Factor of 4 = {1, [U]2[/U], 4}
Factors of 10 = {1, [U]2[/U], 5, 10}
In both of these lists, we see the greatest common factor is 2.
So we divide top and bottom of 4/10 by 2:
4/2 / 10 / 2
[B]2/5
Bob gets 2/5 of a pound of fudge and Sue gets [B]2/5 of a pound of fudge[/B][/B]

c increased by a factor of 20

c increased by a factor of 20
This means we multiply c by 20:
[B]20c[/B]

Claire bought 180 candies and 140 pens for goody bags for her birthday. What is the largest number o

Claire bought 180 candies and 140 pens for goody bags for her birthday. What is the largest number of goody bags that Claire can make so that each goody bag has the same number of candies and the same number of pens? (All candies and pens should be used.)
We want the greatest common factor of 180 and 140. When we [URL='https://www.mathcelebrity.com/gcflcm.php?num1=140&num2=180&num3=&pl=GCF+and+LCM']run GCF(180,140) in our calculator[/URL], we get 20.
We divide our total candies and total pens by our GCF. So each bag has the following:
Candies: 180/20 = [B]9 candies[/B]
Pens: 140/20 = [B]7 pens[/B]

Counting

Free Counting Calculator - Counts up from a number to another number using a factor

Counts down from one number to another number using a factor. Also known as skip counting.

Counts down from one number to another number using a factor. Also known as skip counting.

Derangements - Subfactorials

Free Derangements - Subfactorials Calculator - Calculates the number of derangements/subfactorial !n.

Difference of Two Squares

Free Difference of Two Squares Calculator - Factors a difference of squares binomial in the form a^{2} - b^{2} or multiplies 2 binomials through in the form (ax + by)(ax - by).

Factorials

Free Factorials Calculator - Calculates the following factorial items:

* A factorial of one number such as n!

* A factorial of a numerator divided by a factorial of a denominator such as n!m!/a!b!

* Double Factorials such as n!!

* Stirlings Approximation for n!

* A factorial of one number such as n!

* A factorial of a numerator divided by a factorial of a denominator such as n!m!/a!b!

* Double Factorials such as n!!

* Stirlings Approximation for n!

Factoring and Root Finding

Free Factoring and Root Finding Calculator - This calculator factors a binomial including all 26 variables (a-z) using the following factoring principles:

* Difference of Squares

* Sum of Cubes

* Difference of Cubes

* Binomial Expansions

* Quadratics

* Factor by Grouping

* Common Term

This calculator also uses the Rational Root Theorem (Rational Zero Theorem) to determine potential roots

* Factors and simplifies Rational Expressions of one fraction

* Determines the number of potential*positive* and *negative* roots using Descarte’s Rule of Signs

* Difference of Squares

* Sum of Cubes

* Difference of Cubes

* Binomial Expansions

* Quadratics

* Factor by Grouping

* Common Term

This calculator also uses the Rational Root Theorem (Rational Zero Theorem) to determine potential roots

* Factors and simplifies Rational Expressions of one fraction

* Determines the number of potential

Factorization

Free Factorization Calculator - Given a positive integer, this calculates the following for that number:

1) Factor pairs and prime factorization and prime power decomposition

2) Factors and Proper Factors 3) Aliquot Sum

1) Factor pairs and prime factorization and prime power decomposition

2) Factors and Proper Factors 3) Aliquot Sum

Factors of 36 between 2 and 12

Factors of 36 between 2 and 12
We type in [I][URL='https://www.mathcelebrity.com/factoriz.php?num=36&pl=Show+Factorization']factors of 36[/URL][/I] into our search engine and we get:
{1, 2, 3, 4, 6, 9, 12, 18, 36}
The problem asks for factors of 36 between 2 and 12:
Between does not mean inclusive, so we have anything greater than 2 and less than 12:
[B]{3, 4, 6, 9}[/B]

Find r in P(7, r)

Find r in P(7, r)
Recall the permutations formula:
7! / (7-r!) = 840.
We [URL='https://www.mathcelebrity.com/factorial.php?num=7!&pl=Calculate+factorial']run 7! through our search engine[/URL] and we get:
[URL='https://www.mathcelebrity.com/factorial.php?num=7!&pl=Calculate+factorial']7![/URL] = 5040
5040 / (7 - r)! = 840
Cross multiply, and we get:
5040/840 = 7 - r!
6 = (7 - r)!
Since 6 = 3*2*! = 3!, we have;
3! = (7 - r)!
3 = 7 - r
To solve for r, we [URL='https://www.mathcelebrity.com/1unk.php?num=3%3D7-r&pl=Solve']type this equation into our search engine[/URL] and we get:
r = [B]4[/B]

Find the greatest common factor without a calculator

Find the greatest common factor without a calculator
Check out this table stacking method and the product of factors.
[MEDIA=youtube]3Zjo0XRD6fw[/MEDIA]

Find the greatest number which divides 845 and 1250

Find the greatest number which divides 845 and 1250
This is the greatest common factor. We [URL='https://www.mathcelebrity.com/gcflcm.php?num1=845&num2=1250&num3=&pl=GCF+and+LCM']type GCF(845,1250) into our search engine [/URL]and we get:
[B]5[/B]

Find the last digit of 7^2013

Consider the first 8 calculations of 7 to an exponent:
[LIST]
[*]7^1 = 7
[*]7^2 = 49
[*]7^3 = 343
[*]7^4 = 2,401
[*]7^5 = 16,807
[*]7^6 = 117,649
[*]7^7 = 823,543
[*]7^8 = 5,764,801
[/LIST]
Take a look at the last digit of the first 8 calculations:
7, 9, 3, 1, 7, 9, 3, 1
The 7, 9, 3, 1 repeats through infinity.
So every factor of 4, the cycle of 7, 9, 3, 1 restarts.
Counting backwards from 2013, we know that 2012 is the largest number divisible by 4:
7^2013 = 7^2012 * 7^1
The cycle starts over after 2012.
Which means the last digit of 7^2013 = [B]7
[MEDIA=youtube]Z157jj8R7Yc[/MEDIA][/B]

Find two numbers that add up to 18 and multiply to give 72

Using our [URL='https://www.mathcelebrity.com/factoriz.php?num=72&pl=Show+Factorization']factor calculator[/URL], we get:
6 & 12
[MEDIA=youtube]91JpmUfNBb4[/MEDIA]

George and William both ran a one mile race. William won the race with a time of 4 minutes and 30 se

George and William both ran a one mile race. William won the race with a time of 4 minutes and 30 seconds. If George was 480 feet behind William when the race finished, how long did it take George to run the entire mile? (George continued to run at the same pace.)
When the race was done, George completed:
5280 feet in a mile - 480 feet = 4800 feet
set up a proportion of distance traveled to time where n is the time needed to run the mile
4800/4.5 = 5280/n
Using our [URL='https://www.mathcelebrity.com/proportion-calculator.php?num1=4800&num2=5280&den1=4.5&den2=n&propsign=%3D&pl=Calculate+missing+proportion+value']proportion calculator,[/URL] we get:
n = 4.95
5280/4800 = 1.1
Setup another proportion with the 1.1 factor of distance to time:
4800 * 1.1/4.5 * 1.1 = 5280/4.95
4.95 = 4 minutes and .95*60 seconds
4.95 = [B]4 minutes and 57 seconds[/B]

Greatest Common Factor and Least Common Multiple

Free Greatest Common Factor and Least Common Multiple Calculator - Given 2 or 3 numbers, the calculator determines the following:

* Greatest Common Factor (GCF) using Factor Pairs

* Rewrite Sum using the Distributive Property and factoring out the GCF

* Least Common Multiple (LCM) / Least Common Denominator (LCD) using Factor Pairs

* GCF using the method of Successive Division

* GCF using the Prime Factorization method

* Determine if the numbers are coprime and twin prime

* Greatest Common Factor (GCF) using Factor Pairs

* Rewrite Sum using the Distributive Property and factoring out the GCF

* Least Common Multiple (LCM) / Least Common Denominator (LCD) using Factor Pairs

* GCF using the method of Successive Division

* GCF using the Prime Factorization method

* Determine if the numbers are coprime and twin prime

Greatest Common Factors of Monomials

Free Greatest Common Factors of Monomials Calculator - This calculator will determine the Greatest Common Factors of a set of Monomials

gy=-g/v+w for g

gy=-g/v+w for g
Multiply each side of the equation by v to eliminate fractions:
gvy = -g + vw
Add g to each side:
gvy + g = -g + g + vw
Cancel the g's on the right side and we geT:
gvy + g = vw
Factor out g on the left side:
g(vy + 1) = vw
Divide each side of the equation by (vy + 1):
g(vy + 1)/(vy + 1) = vw/(vy + 1)
Cancel the (vy + 1) on the left side and we geT:
g = [B]vw/(vy + 1)[/B]

Harry got 42 out of 49 correct in his test. What fraction of the marks did he get correct?

Harry got 42 out of 49 correct in his test. What fraction of the marks did he get correct?
The fraction correct is:
42/49
Both the numerator and denominator [URL='http://www.mathcelebrity.com/gcflcm.php?num1=42&num2=49&num3=&pl=GCF']have a common factor[/URL] of 7
Reducing top and bottom by 7, we get:
[B]6/7[/B]

How many different ways could you arrange 5 books on a shelf

How many different ways could you arrange 5 books on a shelf?
[URL='https://www.mathcelebrity.com/factorial.php?num=5!&pl=Calculate+factorial']Using permutations, you can type in 5![/URL] and we get:
[B]120 different ways.[/B]

How many factors does 36 have

How many factors does 36 have
We can type in [URL='https://www.mathcelebrity.com/factoriz.php?num=36&pl=Show+Factorization']factor 36[/URL] into our math engine and we get:
{1, 2, 3, 4, 6, 9, 12, 18, 36}
1 * 36
2 * 18
3 * 12
4 * 9
6 * 6
This set contains [B]9 factors[/B].

How many ways can 5 people be seated in 5 seats?

How many ways can 5 people be seated in 5 seats?
We have the permutation 5!.
Because the first seat can have 5 different people.
The next seat has 5 - 1 = 4 people since one person is in the first seat
The next seat can have 5 - 2 = 3 people since we have two people in the first two seats
The next seat can have 5 - 3 = 2 people since we have three people in the first three seats
The next seat can have 5 - 4 = 1 people since we have four people in the first four seats
[URL='https://www.mathcelebrity.com/factorial.php?num=5!&pl=Calculate+factorial']Type in 5! into our search engine[/URL], and we get 120.

Identify a pair of factors of -35 that has a sum of -2

Identify a pair of factors of -35 that has a sum of -2.
If we [URL='https://www.mathcelebrity.com/factoriz.php?num=-35&pl=Show+Factorization']type in [I]factor -35[/I] into our search engine[/URL], we see 4 factor pairs.
When we add up the factors for each pair, we see [B]7, -5[/B] added together gives us 2.

If 4x+7=xy-6, then what is the value of x, in terms of y

If 4x+7=xy-6, then what is the value of x, in terms of y
Subtract xy from each side:
4x + 7 - xy = -6
Add 7 to each side:
4x - xy = -6 - 7
4x - xy = -13
Factor out x:
x(4 - y) = -13
Divide each side of the equation by (4 - y)
[B]x = -13/(4 - y)[/B]

if a + b = 2 and a2 - b2 = -4, what is the value of a - b?

if a+b=2 and a2-b2=-4, what is the value of a-b?
a^2 - b^2 = -4
Factor this:
(a + b)(a - b) = -4
We know from above, (a +b) = 2, so substitute:
2(a - b) = -4
Divide each side by 2
[B](a - b) = -2[/B]

If a is an even integer and b is an odd integer then prove a ? b is an odd integer

If a is an even integer and b is an odd integer then prove a ? b is an odd integer
Let a be our even integer
Let b be our odd integer
We can express a = 2x (Standard form for even numbers) for some integer x
We can express b = 2y + 1 (Standard form for odd numbers) for some integer y
a - b = 2x - (2y + 1)
a - b = 2x - 2y - 1
Factor our a 2 from the first two terms:
a - b = 2(x - y) - 1
Since x - y is an integer, 2(x- y) is always even. Subtracting 1 makes this an odd number.
[MEDIA=youtube]GDVuQ7bGHx8[/MEDIA]

If a+b=16, then what is 3a+3b=

If a+b=16, then what is 3a+3b=
Factor 3a + 3b:
3(a + b)
Since we know a+b = 16, we have:
3(16) = [B]48[/B]

If f(x) = 3x + 1 and g(x) = x^2 + 2x, find x when f(g(x)) = 10

If f(x) = 3x + 1 and g(x) = x^2 + 2x, find x when f(g(x)) = 10
[U]Evaluate f(g(x))[/U]
f(g(x)) = 3(x^2 + 2x) + 1
f(g(x)) = 3x^2 + 6x + 1
[U]When f(g(x)) = 10, we have[/U]
10 = 3x^2 + 6x + 1
[U]Subtract 10 from each side:[/U]
3x^2 + 6x - 9 = 0
Divide each side of the equation by 3
x^2 + 2x - 3 = 0
Factor, we have: (x + 3)(x - 1) = 0
So x is either [B]1 or -3[/B]

If you can buy 1?3 of a box of chocolates for 6 dollars, how much can you purchase for 4 dollars? Wr

If you can buy 1?3 of a box of chocolates for 6 dollars, how much can you purchase for 4 dollars? Write your answer as a fraction of a box.
Set up a proportion of dollars to boxes where b is the number of boxes for $4:
6/1/3 = 4/b
Cross multiply:
6b = 4/3
Multiply each side by 1/6 to isolate b:
b = 4/18
[URL='https://www.mathcelebrity.com/gcflcm.php?num1=4&num2=18&num3=&pl=GCF+and+LCM']Type in GCF(4,18) into the search engine[/URL]. We get a greatest common factor of 2.
Divide 4 and 18 in the fraction by 2. We get the reduced fraction of:
[B]b = 2/9[/B]

In 2016, National Textile installed a new textile machine in one of its factories at a cost of $300,

In 2016, National Textile installed a new textile machine in one of its factories at a cost of $300,000. The machine is depreciated linearly over 10 years with a scrap value of $10,000. (a) Find an expression for the textile machines book value in the t?th year of use (0 ? t ? 10)
We have a straight line depreciation. Book Value is shown on the [URL='http://www.mathcelebrity.com/depsl.php?d=&a=300000&s=10000&n=10&t=3&bv=&pl=Calculate']straight line depreciation calculator[/URL].

In a factory that manufactures tires, a machine responsible for molding the tire has a failure rate

In a factory that manufactures tires, a machine responsible for molding the tire has a failure rate of 0.2%. If 1,000 tires are produced in a day, of which 6 are faulty, what is the difference between the experimental probability and the theoretical probability?
Theoretical probability = Failure Rate * Tires
Theoretical probability = 0.002 * 1000
Theoretical probability = 2
The experimental probability was given as 6, so the difference is:
6 - 2 = [B]4[/B]

In Trina's desk drawer, there are 15 paper clips and 18 rubber bands. In Kirk's office supply tray,

In Trina's desk drawer, there are 15 paper clips and 18 rubber bands. In Kirk's office supply tray, there are 13 paper clips and 16 rubber bands. Who has a higher ratio of paper clips to rubber bands?
Trina: 15/18
Kirk: 13/16
We want common denominators to compare, so we get a greatest common factor (GCF) for 16 and 18.
[URL='https://www.mathcelebrity.com/gcflcm.php?num1=16&num2=18&num3=&pl=GCF+and+LCM']Running this through our search engine[/URL], we get GCF(16, 18) = 144
For Trina, 144/18 = 8
For Kirk, 144/16 = 9
We multiply Trina's fraction, top and bottom by 8:
15 * 8 / 18 * 8
120/144
We multiply Trina's fraction, top and bottom by 8:
13 * 8 / 16 * 8
104/144
[B]Trina[/B] has more in her numerator, so her ratio of paper clips to rubber bands is greater.

Is it correct to word "10% * 50 + 50" as "10% upper 50"?

If we factor your expression, we get:
y > x(10% + 1)
y> 1.1x Since 10% is 0.1
I read it as y > 110% of x

Jack is making snack bags. He has 18 baby carrots and 42 pretzels. He wants to divide them equally a

Jack is making snack bags. He has 18 baby carrots and 42 pretzels. He wants to divide them equally among the bags. What is the greatest number of snack bags he can make?
Find the [URL='http://www.mathcelebrity.com/gcflcm.php?num1=18&num2=42&num3=&pl=GCF']Greatest Common Factor[/URL] of (18, 42) = 6
6 bags for 18 carrots = 3 carrots per bag
6 bags for 42 pretzels = 7 pretzels per bag
[B]6 bags is the answer[/B]

log5 = 0.699, log2 = 0.301. Use these values to evaluate log40

log5 = 0.699, log2 = 0.301. Use these values to evaluate log40.
One of the logarithmic identities is: log(ab) = log(a) + log(b). Using the numbers 2 and 5, we somehow need to get to 40.
[URL='http://www.mathcelebrity.com/factoriz.php?num=40&pl=Show+Factorization']List factors of 40[/URL].
On the link above, take a look at the bottom where it says prime factorization. We have:
40 = 2 x 2 x 2 x 5
Using our logarithmic identity, we have:
log40 = log(2 x 2 x 2 x 5)
Rewriting this using our identity, we have:
log40 = log2 + log2 + log2 + log5
log40 = 0.301 + 0.301 + 0.301 + 0.699
log40 = [B]1.602
[MEDIA=youtube]qyG_Jkf9VDc[/MEDIA][/B]

Make 19 using only four four's

Make 19 using only four four's
4!-4-4/4
To prove our work, we have:
[URL='https://www.mathcelebrity.com/factorial.php?num=4!&pl=Calculate+factorial']4![/URL] = 24
24 - 4 = 20
Since 4/4 = 1, we have:
20 - 1 = 19

Mrs. Taylor is making identical costumes for the dancers in the dance club. She uses 126 pink ribbon

Mrs. Taylor is making identical costumes for the dancers in the dance club. She uses 126 pink ribbons and 108 yellow ribbons.
a) What is the maximum possible number of costumes she can make?
b) How many pink and how many yellow ribbons are on each costume?
a), we want the greatest common factor (GCF) of 108 and 126. [URL='https://www.mathcelebrity.com/gcflcm.php?num1=108&num2=126&num3=&pl=GCF+and+LCM']Using our GCF calculator[/URL] we get:
[B]a) 18 costumes
[/B]
b)
Pink Ribbons per costume = Total Pink Ribbons / GCF in question a
Pink Ribbons per costume = 126/18
Pink Ribbons per costume = [B]7[/B]
[B][/B]
Yellow Ribbons per costume = Total Yellow Ribbons / GCF in question a
Yellow Ribbons per costume = 108/18
Yellow Ribbons per costume = [B]6[/B]

Multifactorials

Free Multifactorials Calculator - Calculates the multifactorial n!^{(m)}

n is a factor of 16

n is a factor of 16
List out factor of 16:
1 * 16
2 * 8
4 * 4
From the list above, we take the 5 [U]unique[/U] factors and build a set for n:
n = [B]{1, 2, 4, 8, 16}[/B]

natural numbers that are factors of 16

natural numbers that are factors of 16
Natural numbers are positive integers starting at 1.
{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
Of these, [URL='https://www.mathcelebrity.com/factoriz.php?num=16&pl=Show+Factorization']the only factors of 16[/URL] are:
{[B]1, 2, 4, 8, 16}[/B]

n^2+n = odd

n^2+n = odd
Factor n^2+n:
n(n + 1)
We have one of two scenarios:
[LIST=1]
[*]If n is odd, then n + 1 is even. The product of an odd and even number is an even number
[*]If n is even, then n + 1 is odd. The product of an even and odd number is an even number
[/LIST]

n^2-n = even

n^2-n = even
Factor n^2-n:
n(n - 1)
We have one of two scenarios:
[LIST=1]
[*]If n is odd, then n - 1 is even. The product of an odd and even number is an even number
[*]If n is even, then n - 1 is odd. The product of an even and odd number is an even number
[/LIST]

P is the natural numbers that are factors of 25

P is the natural numbers that are factors of 25
we type in [I][URL='https://www.mathcelebrity.com/factoriz.php?num=25&pl=Show+Factorization']factor 25[/URL][/I] into our math engine and we get:
{1, 5, 25}
Since [U]all[/U] of these are natural numbers, our answer is:
[B]{1, 5, 25}[/B]

p/q = f/q- f for f

p/q = f/q- f for f
Isolate f in this literal equation.
Factor out f on the right side:
p/q = f(1/q - 1)
Rewriting the term in parentheses, we get:
p/q = f(1 - q)/q
Cross multiply:
f = pq/q(1 - q)
Cancelling the q/q on the right side, we get:
f = [B]p/(1 - q)[/B]

p/q=f/q-f for f

p/q=f/q-f for f
To solve this literal equation for f, let's factor out f on the right side:
p/q=f(1/q-1)
Divide each side by (1/q - 1)
p/(q(1/q - 1)) = f(1/q-1)/(1/q - 1)
Cancelling the (1/q - 1) on the right side, we get:
f = p/(1/q - 1)
Rewriting this since (1/q -1) = (1 - q)/q since q/q = 1 we have:
f = [B]pq/(1 - q)[/B]

Prove 0! = 1

Prove 0! = 1
Let n be a whole number, where n! represents the product of n and all integers below it through 1.
The factorial formula for n is:
n! = n · (n - 1) * (n - 2) * ... * 3 * 2 * 1
Written in partially expanded form, n! is:
n! = n * (n - 1)!
[U]Substitute n = 1 into this expression:[/U]
n! = n * (n - 1)!
1! = 1 * (1 - 1)!
1! = 1 * (0)!
For the expression to be true, 0! [U]must[/U] equal 1. Otherwise, 1! <> 1 which contradicts the equation above

Prove 0! = 1

[URL='https://www.mathcelebrity.com/proofs.php?num=prove0%21%3D1&pl=Prove']Prove 0! = 1[/URL]
Let n be a whole number, where n! represents:
The product of n and all integers below it through 1.
The factorial formula for n is
n! = n · (n - 1) · (n - 2) · ... · 3 · 2 · 1
Written in partially expanded form, n! is:
n! = n · (n - 1)!
[SIZE=5][B]Substitute n = 1 into this expression:[/B][/SIZE]
n! = n · (n - 1)!
1! = 1 · (1 - 1)!
1! = 1 · (0)!
For the expression to be true, 0! [U]must[/U] equal 1.
Otherwise, 1! ? 1 which contradicts the equation above
[MEDIA=youtube]wDgRgfj1cIs[/MEDIA]

Prove that the difference between alternate consecutive squares as always even

Take an integer n. The next alternate consecutive integer is n + 2
Subtract the difference of the squares:
(n + 2)^2 - n^2
n^2 + 4n + 4 - n^2
n^2 terms cancel, we get:
4n + 4
Factor out a 4:
4(n + 1)
If n is odd, n + 1 is even. 4 * even is always even
If n is even, n + 1 is odd. 4 * odd is always odd
Since both cases are even, we've proven our statement.
[MEDIA=youtube]J_E9lR5qFY0[/MEDIA]

Prove that the difference of two consecutive cubes is never divisible by 3

Take two consecutive integers:
n, n + 1
The difference of their cubes is:
(n + 1)^3 - n^3
n^3 + 3n^2 + 3n + 1 - n^3
Cancel the n^3
3n^2 + 3n + 1
Factor out a 3 from the first 2 terms:
3(n^2 + n) + 1
The first two terms are always divisible by 3 but then the + 1 makes this expression not divisible by 3:
3(n^2 + n) + 1 = 1 (mod 3)
[MEDIA=youtube]hFvJ3epqmyE[/MEDIA]

Prove the sum of two odd numbers is even

Take two arbitrary integers, x and y
We can express the odd integer x as 2a + 1 for some integer a
We can express the odd integer y as 2b + 1 for some integer b
x + y = 2a + 1 + 2b + 1
x + y = 2a + 2b + 2
Factor out a 2:
x + y = 2(a + b + 1)
Since 2 times any integer even or odd is always even, then [B]x + y by definition is even[/B].
[MEDIA=youtube]9A-qe4yZXYw[/MEDIA]

Prove there is no integer that is both even and odd

Let us take an integer x which is both even [I]and[/I] odd.
[LIST]
[*]As an even integer, we write x in the form 2m for some integer m
[*]As an odd integer, we write x in the form 2n + 1 for some integer n
[/LIST]
Since both the even and odd integers are the same number, we set them equal to each other
2m = 2n + 1
Subtract 2n from each side:
2m - 2n = 1
Factor out a 2 on the left side:
2(m - n) = 1
By definition of divisibility, this means that 2 divides 1.
But we know that the only two numbers which divide 1 are 1 and -1.
Therefore, our original assumption that x was both even and odd must be false.
[MEDIA=youtube]SMM9ubEVcLE[/MEDIA]

Quadratic Equations and Inequalities

Free Quadratic Equations and Inequalities Calculator - Solves for quadratic equations in the form ax^{2} + bx + c = 0. Also generates practice problems as well as hints for each problem.

* Solve using the quadratic formula and the discriminant Δ

* Complete the Square for the Quadratic

* Factor the Quadratic

* Y-Intercept

* Vertex (h,k) of the parabola formed by the quadratic where h is the Axis of Symmetry as well as the vertex form of the equation a(h - h)^{2} + k

* Concavity of the parabola formed by the quadratic

* Using the Rational Root Theorem (Rational Zero Theorem), the calculator will determine potential roots which can then be tested against the synthetic calculator.

* Solve using the quadratic formula and the discriminant Δ

* Complete the Square for the Quadratic

* Factor the Quadratic

* Y-Intercept

* Vertex (h,k) of the parabola formed by the quadratic where h is the Axis of Symmetry as well as the vertex form of the equation a(h - h)

* Concavity of the parabola formed by the quadratic

* Using the Rational Root Theorem (Rational Zero Theorem), the calculator will determine potential roots which can then be tested against the synthetic calculator.

Sarah rolls 2 fair dice and adds the results from each. Work out the probability of getting a total

Sarah rolls 2 fair dice and adds the results from each. Work out the probability of getting a total that is a factor of 6.
Factors of 6 are {6, 12}
[URL='https://www.mathcelebrity.com/2dice.php?gl=1&pl=6&opdice=1&rolist=+&dby=&ndby=&montect=+']P(Roll a 6)[/URL] = 5/36
[URL='https://www.mathcelebrity.com/2dice.php?gl=1&pl=12&opdice=1&rolist=+&dby=&ndby=&montect=+']P(Roll a 12)[/URL] = 1/36
P(Roll a 6 or Roll a 12) = P(Roll a 6) + P(Roll a 12)
P(Roll a 6 or Roll a 12) = 5/36 + 1/36
P(Roll a 6 or Roll a 12) = 6/36
Using our [URL='https://www.mathcelebrity.com/fraction.php?frac1=6%2F36&frac2=3%2F8&pl=Simplify']fraction simplifier[/URL], we see that:
P(Roll a 6 or Roll a 12) = [B]1/6[/B]

Simplify 7sqrt(3) - sqrt(12)

7sqrt(3) is broken down.
sqrt(12) is not broken down. Let's find all the factors of 12 and see if we stumble on a perfect square:
[LIST]
[*]1 * 12
[*]2 * 6
[*]3 * 4
[/LIST]
4 is a perfect square, since sqrt(4) = 2.
So sqrt(12) = sqrt(3 * 4)
We pull the sqrt(4) = 2 outside the radical and rewrite our problem as:
7sqrt(3) - 2sqrt(3)
These are like terms, so we have:
(7 - 2)sqrt(3)
[B]5sqrt(3) [/B]
[MEDIA=youtube]ljXVXWnKiWY[/MEDIA]

Soda cans are sold in a local store for 50 cents each. The factory has $900 in fixed costs plus 25 c

Soda cans are sold in a local store for 50 cents each. The factory has $900 in fixed costs plus 25 cents of additional expense for each soda can made. Assuming all soda cans manufactured can be sold, find the break-even point.
Calculate the revenue function R(c) where s is the number of sodas sold:
R(s) = Sale Price * number of units sold
R(s) = 50s
Calculate the cost function C(s) where s is the number of sodas sold:
C(s) = Variable Cost * s + Fixed Cost
C(s) = 0.25s + 900
Our break-even point is found by setting R(s) = C(s):
0.25s + 900 = 50s
We [URL='https://www.mathcelebrity.com/1unk.php?num=0.25s%2B900%3D50s&pl=Solve']type this equation into our search engine[/URL] and we get:
s = [B]18.09[/B]

Squaring a number equals 5 times that number

Squaring a number equals 5 times that number.
The phrase [I]a number[/I] means an arbitrary variable, let's call it x.
Squaring this number:
x^2
5 times this number means we multiply by 5:
5x
The phrase [I]equals[/I] means we set both expressions equal to each other:
[B]x^2 = 5x [/B] <-- This is our algebraic expression
If you want to solve for x, then we subtract 5x from each side:
x^2 - 5x = 5x - 5x
Cancel the 5x on the right side, leaving us with 0:
x^2 - 5x = 0
Factor out x:
x(x - 5)
So we get x = 0 or [B]x = 5[/B]

Synthetic Division

Free Synthetic Division Calculator - Using Ruffinis Rule, this performs synthetic division by dividing a polynomial with a maximum degree of 6 by a term (x ± c) where c is a constant root using the factor theorem. The calculator returns a quotient answer that includes a remainder if applicable. Also known as the Rational Zero Theorem

The coach writes the batting order on a piece of paper. How many different ways could the list be wr

The coach writes the batting order on a piece of paper. How many different ways could the list be written?
We have 9 people in a line up. The total lineups are shown by:
9 * 8 * 7 * ... * 2 * 1
Or, 9!. [URL='https://www.mathcelebrity.com/factorial.php?num=9!&pl=Calculate+factorial']Typing 9! in our search engine[/URL] and we get [B]362,880[/B]

The doubling time of a population of flies is 8 hours by what factor does a population increase in 2

The doubling time of a population of flies is 8 hours.
a) By what factor does a population increase in 24 hours?
b) By what factor does the population increase in 2 weeks?
a) If the population doubles every 8 hours, then it doubles 3 times in 24 hours, since 24/8 = 3.
So 2 * 3 = 6. The increase factor is [B]6[/B]
b) Since a) is one full day, we now need to know how much it doubles in 14 days, which is 2 weeks. We take our factor of 6 for each day, and multiply it by 14: 14 * 6 = [B]84[/B]

The earth makes a full rotation in 24 hours. Jupiter takes approximately 58 days, 15 h, and 30 min t

The earth makes a full rotation in 24 hours. Jupiter takes approximately 58 days, 15 h, and 30 min to complete a full rotation. How many hours does it take Jupiter to complete a full rotation? Show your work using the correct conversion factors.
Convert 58 days, 15 h, and 30 min to hours.
[LIST=1]
[*]Type [URL='https://www.mathcelebrity.com/timecon.php?quant=58&pl=Calculate&type=day']58 days[/URL] into the search engine to get 1,392 hours.
[*]Add 15 hours to get 1,392 + 15 = 2,007 hours
[*]Now convert the 30 min to hours. [URL='https://www.mathcelebrity.com/timecon.php?quant=30&pl=Calculate&type=minute']Type 30 minutes into the search engine[/URL] to get 0.5 hours
[*]Add up (1), (2), and (3) to get 1,392 + 15 + 0.5 = [B]2007.5[/B] hours for a full rotation.
[/LIST]

The next number in the series 38 36 30 28 22 is

The next number in the series 38 36 30 28 22 is
Notice the change of factors.
Subtract 2, Subtract 6, Subtract 2, Subtract 6.
So the next number should subtract 2.
22 - 2 = [B]20
[MEDIA=youtube]x7SHk_6-aok[/MEDIA][/B]

The Palafoxes make $3,840 a month. They spend $1,600 for rent. What fraction of their income goes to

The Palafoxes make $3,840 a month. They spend $1,600 for rent. What fraction of their income goes to rent?
Rent Payment Fraction = Rent Payment / Total Income
Rent Payment Fraction = 1600 / 3840
Our greatest common factor of 1600 and 3840 is 320.
So if we divide 1600 and 3840 by 320, we get:
Rent Payment Fraction = [B]5/12
[MEDIA=youtube]DsXk6AKT18M[/MEDIA][/B]

The product of two positive numbers is 96. Determine the two numbers if one is 4 more than the other

The product of two positive numbers is 96. Determine the two numbers if one is 4 more than the other.
Let the 2 numbers be x and y.
We have:
[LIST=1]
[*]xy = 96
[*]x = y - 4
[/LIST]
[U]Substitute (2) into (1)[/U]
(y - 4)y = 96
y^2 - 4y = 96
[U]Subtract 96 from both sides:[/U]
y^2 - 4y - 96 = 0
[U]Factoring using our quadratic calculator, we get:[/U]
(y - 12)(y + 8)
So y = 12 and y = -8. Since the problem states positive numbers, we use [B]y = 12[/B].
Substituting y = 12 into (2), we get:
x = 12 - 4
[B]x = 8[/B]
[B]We have (x, y) = (8, 12)[/B]

There are 72 boys and 90 girls on the Math team For the next math competition Mr Johnson would like

There are 72 boys and 90 girls on the Math team For the next math competition Mr Johnson would like to arrange all of the students in equal rows with only girls or boys in each row with only girls or boys in each row. What is the greatest number of students that can be put in each row?
To find the maximum number (n) of boys or girls in each row, we want the GCF (Greatest Common Factor) of 72 and 90.
[URL='https://www.mathcelebrity.com/gcflcm.php?num1=72&num2=90&num3=&pl=GCF+and+LCM']Using our GCF calculator for GCF(72,90)[/URL], we get 18.
[LIST]
[*]72 boys divided by 18 = [B]4 rows of boys[/B]
[*]90 girls divided by 18 = [B]5 rows of girls[/B]
[/LIST]

What is the average of 7 consecutive numbers if the smallest number is called n?

What is the average of 7 consecutive numbers if the smallest number is called n?
[LIST]
[*]First number = n
[*]Second number = n + 1
[*]Third number = n + 2
[*]Fourth number = n + 3
[*]Fifth number = n + 4
[*]Sixth number = n + 5
[*]Seventh number = n + 6
[/LIST]
Average = Sum of all numbers / Total numbers
Average = (n + n + 1 + n + 2 + n + 3 + n + 4 + n + 5 + n + 6)/7
Average = 7n + 21/7
Factor out a 7 from the top:
7(n + 3)/7
Cancel the 7's:
[B]n + 3[/B]

What pair of factors of -28 has a sum of -3

What pair of factors of -28 has a sum of -3?
We type in [I]factor -28[/I] into our search engine.
Scrolling down the list of factor sums, we see:
-7 + 4 = -3
So our answer is [B](-7, 4)[/B]

Wind Chill Factor

Free Wind Chill Factor Calculator - This calculator determines the wind chill factor given a temperature in F° and a wind speed in miles per hour (mph). Simply enter your temperature and wind speed and press the button

Write in set builder form {all possible numbers formed by any two of the digits 1 2 5}

Write in set builder form {all possible numbers formed by any two of the digits 1 2 5}
With 3 numbers, we got [URL='https://www.mathcelebrity.com/factorial.php?num=3!&pl=Calculate+factorial']3! = 6[/URL] possible numbers formed by the two digits
[LIST=1]
[*]12
[*]15
[*]21
[*]25
[*]51
[*]52
[/LIST]
In set builder notation, we write this as:
{x : x ? {12, 15, 21, 25, 51, 52})
x such that x is a element of the set {12, 15, 21, 25, 51, 52}

wy - ma = ay/n for y

wy - ma = ay/n for y
Subtract ay/n from each side:
wy - ma - ay/n = ay/n - ay/n
wy - ma - ay/n = 0
Now add ma to each side:
wy - ay/n = ma
Factor out y:
y(w - a/n) = ma
Divide each side by (w - a/n)
y = [B]ma/(w - a/n)[/B]

you and 5 friends go to a concert. how many different ways can you sit in the assigned seats

You and 5 friends go to a concert. how many different ways can you sit in the assigned seats?
With 6 possible seats, the [URL='https://www.mathcelebrity.com/factorial.php?num=6!&pl=Calculate+factorial']number of unique arrangements is[/URL]:
6! = 6 x 5 x 4 x 3 x 2 x 1 = [B]720[/B]

You are making identical gift bags using 24 candles and 36 bottles of lotion. What is the greatest n

You are making identical gift bags using 24 candles and 36 bottles of lotion. What is the greatest number of gift bags you can make with no items left over?
We take the greatest common factor [URL='https://www.mathcelebrity.com/gcflcm.php?num1=24&num2=36&num3=&pl=GCF+and+LCM']GCF (24, 36) = 12[/URL]
So we have a ratio of 24/12 = 2 candles and 36/12 = 3 bottles of lotion per bag giving us [B]12 bags[/B].

your classmate asserted that x^2 - 4x - 12 and 12 - 4x - x^2 has the same factors is your classmate

your classmate asserted that x^2 - 4x - 12 and 12 - 4x - x^2 has the same factors is your classmate correct
Factor x^2 - 4x - 12 using binomials:
(x + 2)(x - 6)
Therefore, factors are x = -2, x = 6
Factor 12 - 4x - x^2
-(x - 6)(x + 2)
Therefore, factors are x = -2, x = -6
Because they don't have two matching factors, your classmate is [B]incorrect.[/B]

Your salary after a 5% increase if your salary before the increase was s

Your salary after a 5% increase if your salary before the increase was s.
If we start with s, and get a 5% increase, we will have s + 0.05s.
Factor our s:
[B]s(1.05) or 1.05s[/B]

z = (x + y)/mx; Solve for x

z = (x + y)/mx; Solve for x
Cross multiply:
zmx = x + y
Subtract x from each side
zmx - x = y
Factor out x
x(zm - 1) = y
Divide each side by zm - 1
x = y/(zm - 1)
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z/w=x+z/x+y for z

z/w=x+z/x+y for z
This is a literal equation. Let's isolate z on one side.
Subtract z/x from each side.
z/w - z/x = x + y
Factor our z on the left side:
z(1/w - 1/x) = x + y
Divide each side by (1/w - 1/x)
z = x + y/(1/w - 1/x)
To remove reciprocals in the denominator, we rewrite 1/w - 1/x with a common denominator xw
(x - w)/xw
Then multiply x + y by the reciprocal
z = [B](x + y)xw/(x - w)[/B]

zy-dm=ky/t for y

zy-dm=ky/t for y
Isolate terms with y to solve this literal equation.
Subtract zy from each side:
zy - dm - zy = ky/t - zy
Cancel the zy terms on the left side, we get:
-dm = ky/t - zy
Factor out y:
y(k/t - z) = -dm
Divide each side by (k/t - z)
y = -dm/(k/t - z)
(k/t - z) can be rewritten as (k - tz)/t
We multiply -dm by the reciprocal of this quotient to get our simplified literal equation:
y = [B]-dmt/(k - tz)[/B]