72 results

denominator - The bottom portion of a fraction. For a/b, b is the denominator

1, 1/2, 1/4, 1/8, 1/16 The next number in the sequence is 1/32. What is the function machine you wou

1, 1/2, 1/4, 1/8, 1/16
The next number in the sequence is 1/32. What is the function machine you would use to find the nth term of this sequence?
Hint: look at the denominators
We notice that
1/2^0 = 1/1 = 1
1/2^1 = 1/2
1/2^2 = 1/4
1/2^3 = 1/8
1/2^4 = 1/32
So we write our explicit formula for term n:
f(n) = [B]1/2^(n - 1)[/B]

1, 1/2, 1/4, 1/8, 1/16, ...

At first glance, we see powers of 2 in the denominator of every term except the first one.
But if we remember 2^0 = 1, we get our breakthrough.
1/2^0 = 1/1 = 1
Therefore, we stagger the powers of 2 by 1 less than the term we are on:
a(n) = [B]1/2^(n - 1)
[MEDIA=youtube]Ua-arUukOew[/MEDIA][/B]

1/a + 1/b = 1/2 for a

1/a + 1/b = 1/2 for a
Subtract 1/b from each side to solve this literal equation:
1/a + 1/b - 1/b = 1/2 - 1/b
Cancel the 1/b on the left side, we get:
1/a = 1/2 - 1/b
Rewrite the right side, using 2b as a common denominator:
1/a = (b - 2)/2b
Cross multiply:
a(b - 2) = 2b
Divide each side by (b - 2)
a = [B]2b/(b - 2)[/B]

14 is the what of 1/14?

14 is the what of 1/14?
[B]Denominator[/B]

18 divided by the difference of t and 9

The difference of t and 9 is:
t - 9
Now, we set up a quotient with 18 as the numerator and t - 9 as the denominator
18
------
t - 9

3abc^4/12a^3(b^3c^2)^2 * 8ab^-4c/4a^2b

3abc^4/12a^3(b^3c^2)^2 * 8ab^-4c/4a^2b
Expand term 1:
3abc^4/12a^3(b^3c^2)^2
3abc^4/12a^3b^6c^4
Now simplify term 1:
3/12 = 1/4
c^4 terms cancel
Subtract powers from variables since the denominator powers are higher:
b^(6 - 1) = b^5
a^(3 - 1) = a^2
1/4a^2b^5
Now simplify term 2:
8ab^-4c/4a^2b
8/4 = 2
2c/a^(2 - 1)b^(1 - -4)
2c/ab^5
Now multiply simplified term 1 times simplified term 2:
1/4a^2b^5 * 2c/ab^5
(1 * 2c)/(4a^2b^5 * ab^5)
2c/4a^(2 + 1)b^(5 + 5)
2c/4a^3b^10
2/4 = 1/2, so we have:
[B]c/2a^3b^10[/B]

5 times a number increased by 4 is divided by 6 times the same number

5 times a number increased by 4 is divided by 6 times the same number
Take this algebraic expression in parts.
Part 1: 5 times a number increased by 4
[LIST]
[*]The phrase [I]a number[/I] means an arbitrary variable, let's call it x: x
[*]5 times the number means multiply x by 5: 5x
[*][I]Increased by 4[/I] means we add 4 to 5x: 5x + 4
[/LIST]
Part 2: 6 times the same number
[LIST]
[*]From above, [I]a number[/I] is x: x
[*]6 times the number means we multiply x by 6: 6x
[/LIST]
The phrase [I]is divided by[/I] means we have a quotient, where 5x + 4 is the numerator, and 6x is the denominator.
[B](5x + 4)/6x[/B]

A 3 hour river cruise goes 15 km upstream and then back again. The river has a current of 2 km an ho

A 3 hour river cruise goes 15 km upstream and then back again. The river has a current of 2 km an hour. What is the boat's speed and how long was the upstream journey?
[U]Set up the relationship of still water speed and downstream speed[/U]
Speed down stream = Speed in still water + speed of the current
Speed down stream = x+2
Therefore:
Speed upstream =x - 2
Since distance = rate * time, we rearrange to get time = Distance/rate:
15/(x+ 2) + 15 /(x- 2) = 3
Multiply each side by 1/3 and we get:
5/(x + 2) + 5/(x - 2) = 1
Using a common denominator of (x + 2)(x - 2), we get:
5(x - 2)/(x + 2)(x - 2) + 5(x + 2)/(x + 2)(x - 2)
(5x - 10 + 5x + 10)/5(x - 2)/(x + 2)(x - 2)
10x = (x+2)(x-2)
We multiply through on the right side to get:
10x = x^2 - 4
Subtract 10x from each side:
x^2 - 10x - 4 = 0
This is a quadratic equation. To solve it, [URL='https://www.mathcelebrity.com/quadratic.php?num=x%5E2-10x-4%3D0&pl=Solve+Quadratic+Equation&hintnum=+0']we type it in our search engine[/URL] and we get:
Speed of the boat in still water =X=5 +- sq. Root of 29 kmph
We only want the positive solution:
x = 5 + sqrt(29)
x = 10.38
[U]Calculate time for upstream journey:[/U]
Time for upstream journey = 15/(10.38 - 2)
Time for upstream journey = 15/(8.38)
Time for upstream journey = [B]1.79[/B]
[U]Calculate time for downstream journey:[/U]
Time for downstream journey = 15/(10.38 + 2)
Time for downstream journey = 15/(12.38)
Time for downstream journey = [B]1.21[/B]

a = v^2/r for r

a = v^2/r for r
Start by cross multiplying to get r out of the denominator:
ar = v^2
Divide each side of the equation by a to isolate r:
ar/a = v^2/a
Cancel the a's on the left side, and we get:
r = [B]v^2/a[/B]

A boy spent one-half of his money for a book and one-third of his money for a pen. The remaining $2.

A boy spent one-half of his money for a book and one-third of his money for a pen. The remaining $2.25 he saved. How much money did he originally have?
Find out what percent of money was spent
Using a common denominator of 6, we have 1/2 + 1/3 = 3/6 + 2/6 = 5/6.
Therefore, 1/6 of his money is left to save. Let the boy's original money be x. We have:
x/6 = 2.25
Cross multiply, we get x = [B]13.50[/B]

a class has 24 people and 1/6 of them have blue eues. what fraction of the class has blue eyes, usin

a class has 24 people and 1/6 of them have blue eues. what fraction of the class has blue eyes, using 24 as the denominator
Blue eyes = 1/6 * 24
Blue Eyes = 24/6
Blue Eyes = 4
Since 6*4 = 24, we have:
24/6 * 4/4 = [B]96/24[/B]

A company has 12,600 employees. Of these, 1/4 drive alone to work, 1/6 car pool, 1/8 use public tran

A company has 12,600 employees. Of these, 1/4 drive alone to work, 1/6 car pool, 1/8 use public transportation, 1/9 cycle, and the remainder use other methods of transportation. How many employees use each method of transportation?
Find the remainder fraction:
Remainder = 1 - (1/4 + 1/6 + 1/8 + 1/9)
The least common multiple of 4, 6, 8, 9 is 72. So we divide 72 by each fraction denominator to get our multiplier:
1/4 = 18/72
1/6 = 12/72
1/8 = 9/72
1/9 = 8/72
Add those all up:
(18 + 12 + 9 + 8)/72
47/72
Now subtract the other methods out from 1 to get the remainder of who use other methods:
Remainder = 1 - 47/72
Since 1 = 72/72, we have:
(72 - 47)/72
[B]25/72[/B]

A fraction has a value of 3/4. If 7 is added to the numerator, the resulting fraction is equal to th

A fraction has a value of 3/4. If 7 is added to the numerator, the resulting fraction is equal to the reciprocal of the original fraction. Find the original fraction.
Let the fraction be x/y. We're given two equations:
[LIST=1]
[*]x/y = 3/4
[*](x + 7)/y = 4/3. [I](The reciprocal of 3/4 is found by 1/(3/4)[/I]
[/LIST]
Cross multiply equation 1 and equation 2:
[LIST=1]
[*]4x = 3y
[*]3(x + 7) = 4y
[/LIST]
Simplifying, we get:
[LIST=1]
[*]4x = 3y
[*]3x + 21 = 4y
[/LIST]
If we divide equation 1 by 4, we get:
[LIST=1]
[*]x = 3y/4
[*]3x + 21 = 4y
[/LIST]
Substitute equation (1) into equation (2) for x:
3(3y/4) + 21 = 4y
9y/4 + 21 = 4y
Multiply the equation by 4 on both sides to eliminate the denominator:
9y + 84 = 16y
To solve this equation for y, we type it in our math engine and we get:
y = [B]12
[/B]
We then substitute y = 12 into equation 1 above:
x = 3 * 12/4
x = 36/4
x = [B]9
[/B]
So our original fraction x/y = [B]9/12[/B]

A lottery offers 1 $1000 prize and 5 $100 prizes. 1000 tickets are sold. Find the expectation if a p

A lottery offers 1 $1000 prize and 5 $100 prizes. 1000 tickets are sold. Find the expectation if a person buys 1 ticket for $5.
Set up the expected values E(x):
for the 1,000 price:
E(x) = (1000 - 5) * 1/1000 = 995/1000
For the 5 $100 prizes:
E(x) = (100 - 5) * 5/1000 = 475/1000
For the losing ticket. With 6 winning tickets, we have 1000 - 6 = 994 losing tickets:
E(x) = -3 * 994/1000 = -2982/1000
We get our total expected value by adding all of these expected values up. Since they all have the same denominator, we add numerators:
E(x) = (995 + 475 - 2982)/1000
E(x) = -1512/1000
E(x) = [B]-1.51[/B]

A quarter of the learners in a class have blond hair and two thirds have brown hair. The rest of the

A quarter of the learners in a class have blond hair and two thirds have brown hair. The rest of the learners in the class have black hair. How many learners in the class if 9 of them have blonde hair?
Total learners = Blond + Brown + Black
Total Learners = 1/4 + 2/3 + Black
Total Learners will be 1, the sum of all fractions
1/4 + 2/3 + Black = 1
Using common denominators of 12, we have:
3/12 + 8/12 + Black = 12/12
11/12 + Black = 12/12
Subtract 11/12 from each side:
Black = 1/12
Let t be the total number of people in class. We are given for blondes:
1/4t = 9
Multiply each side by 4
[B]t = 36[/B]
Brown Hair
2/3(36) = 24
Black Hair
1/12(36) = 3

A rational expression is undefined when what is 0?

A rational expression is undefined when what is 0?
The [B]denominator[/B]. Because division by zero is undefined.

A rational number is such that when you multiply it by 7/3 and subtract 3/2 from the product, you ge

A rational number is such that when you multiply it by 7/3 and subtract 3/2 from the product, you get 92. What is the number?
Let the rational number be x. We're given:
7x/3 - 3/2 = 92
Using a common denominator of 3*2 = 6, we rewrite this as:
14x/6 - 9/6 = 92
(14x - 9)/6 = 92
Cross multiply:
14x - 9 = 92 * 6
14x - 9 = 552
To solve for x, we [URL='https://www.mathcelebrity.com/1unk.php?num=14x-9%3D552&pl=Solve']type this equation into our search engine [/URL]and we get:
x = [B]40.07[/B]

A recipe calls for 2 ½ cup of flour, but Paul only has 2 ?. How much more flour does he need?

A recipe calls for 2 ½ cup of flour, but Paul only has 2 ?. How much more flour does he need?
Convert to improper fractions
[URL='https://www.mathcelebrity.com/fraction.php?frac1=2%261%2F2&frac2=3%2F8&pl=Simplify']2 & 1/2 [/URL]= 5/2
[URL='https://www.mathcelebrity.com/fraction.php?frac1=2%261%2F6&frac2=3%2F8&pl=Simplify']2 & 1/6[/URL] = 13/6
[URL='https://www.mathcelebrity.com/equivalent-fractions.php?num=5%2F2&pl=Equivalent+Fractions']Convert 5/2 to an equivalent fraction with a denominator[/URL] of 6:
15/6
[URL='https://www.mathcelebrity.com/fraction.php?frac1=15%2F6&frac2=13%2F6&pl=Subtract']We subtract 13/6 from 15/6[/URL]
15/6 - 13/6 = 2/6
2/6 = [B]1/3[/B]

a recipe of 20 bread rolls requires 5 tablespoons of butter. How many tablespoons of butter are need

a recipe of 20 bread rolls requires 5 tablespoons of butter. How many tablespoons of butter are needed for 30 bread rolls?
Set up a proportion of bread rolls per tablespoons of butter where t is the amount of tablespoons of butter needed for 30 bread rolls:
20/5 = 30/t
Cross multiply our proportion:
Numerator 1 * Denominator 2 = Denominator 1 * Numerator 2
20t = 30 * 5
20t = 150
Divide each side of the equation by 20:
20t/20 = 150/20
Cancel the 20's on the left side and we get:
t = [B]7.5[/B]

a son is 1/4 of his fathers age. the difference in their ages is 30. what is the fathers age.

a son is 1/4 of his fathers age. the difference in their ages is 30. what is the fathers age.
Declare variables:
[LIST]
[*]Let f be the father's age
[*]Let s be the son's age
[/LIST]
We're given two equations:
[LIST=1]
[*]s = f/4
[*]f - s = 30. [I]The reason why we subtract s from f is the father is older[/I]
[/LIST]
Using substitution, we substitute equaiton (1) into equation (2) for s:
f - f/4 = 30
To remove the denominator/fraction, we multiply both sides of the equation by 4:
4f - 4f/4 = 30 *4
4f - f = 120
3f = 120
To solve for f, we divide each side of the equation by 3:
3f/3 = 120/3
Cancel the 3's on the left side and we get:
f = [B]40[/B]

a stone mason builds 7 houses in 3 days. How many days does it take to build 11 houses?

a stone mason builds 7 houses in 3 days. How many days does it take to build 11 houses?
The build rate of houses per days is proportional. Set up a proportion of [I]houses to days[/I] where d is the number of days it takes to build 11 houses:
7/3 = 11/d
Cross multiply:
Numerator 1 * Denominator 2 = Denominator 1 * Numerator 2
7d = 11 * 3
7d = 33
Divide each side of the equation by 7:
7d/7 = 33/7
d = [B]4.7142857142857[/B]

Amanda spent 2/5 of her time after school doing homework and ¼ of her remaining time riding her bike

Amanda spent 2/5 of her time after school doing homework and ¼ of her remaining time riding her bike. If she rode her bike for 45 minutes in a week, how much time did she devote to homework in the same week
If Amanda spent 2/5 of her time after school doing homework, she has 1 - 2/5 time left over.
We convert 1 to a fraction using a denominator of 5, we get:
5/5 - 2/5 = 3/5
And Amanda spent 1/4 of 3/5 of her time bike riding, which means she spent:
1(3)/4(5) = 3/20 of her time.
If the total time after school is t, we have:
3t/20 = 45
[URL='https://www.mathcelebrity.com/prop.php?num1=3t&num2=45&den1=20&den2=1&propsign=%3D&pl=Calculate+missing+proportion+value']Typing in 3t/20 = 45 to our search engine[/URL], we get t = 300.
So Amanda has 300 total minutes after school, which means she spent 2/5(300) = [B]120 minutes (2 hours)[/B] doing homework.

An ancient Greek was said to have lived 1/4 of his live as a boy, 1/5 as a youth, 1/3 as a man, and

An ancient Greek was said to have lived 1/4 of his live as a boy, 1/5 as a youth, 1/3 as a man, and spent the last 13 years as an old man. How old was he when he died?
Set up his life equation per time lived as a boy, youth, man, and old man
1/4 + 1/5 + 1/3 + x = 1.
Using our [URL='http://www.mathcelebrity.com/gcflcm.php?num1=4&num2=3&num3=5&pl=LCM']LCM Calculator[/URL], we see the LCM of 3,4,5 is 60. This is our common denominator.
So we have 15/60 + 12/60 + 20/60 + x/60 = 60/60
[U]Combine like terms[/U]
x + 47/60 = 60/60
[U]Subtract 47/60 from each side:[/U]
x/60 = 13/60
x = 13 out of the 60 possible years, so he was [B]60 when he died[/B].

An experienced accountant can balance the books twice as fast as a new accountant. Working together

An experienced accountant can balance the books twice as fast as a new accountant. Working together it takes the accountants 10 hours. How long would it take the experienced accountant working alone?
Person A: x/2 job per hour
Person B: 1/x job per hour
Set up our equation:
1/x + 1/(2x) = 1/10
Multiply the first fraction by 2/2 to get common denominators;
2/(2x) + 1/(2x) = 1/10
Combine like terms
3/2x = 1/10
Cross multiply:
30 = 2x
Divide each side by 2:
[B]x = 15[/B]

Anna painted 1/6 of a wall, Eric painted 1/5 of the wall, and Meadow painted 1/4 of the wall. There

Anna painted 1/6 of a wall, Eric painted 1/5 of the wall, and Meadow painted 1/4 of the wall. There are now 3910 square feet left to paint. How many square feet did Anna paint?
[URL='https://www.mathcelebrity.com/gcflcm.php?num1=4&num2=5&num3=6&pl=LCM']Using 60 as a common denominator through least common multiple[/URL], we get:
1/6 = 10/60
1/5 = 12/60
1/4 = 15/60
10/60 + 12/60 + 15/60 = 37/60
Remaining part of the wall is 60/60 - 37[B]/[/B]60 = 23/60
3910/23 = 170 for each 1/60 of a wall
Anna painted 1/6 or 10/60 of the wall. So we multiply 170 * 10 = [B]1,700 square feet[/B]

at a party, there are 72 people. The ratio of men to ladies to kids is 4 to 3 to 2.

at a party, there are 72 people. The ratio of men to ladies to kids is 4 to 3 to 2.
[LIST]
[*]How many men at the party?
[*]How many ladies at the party?
[*]How many kids at the party?
[/LIST]
Our total ratio denominator is 4 + 3 + 2 = 9. To find the number of each type of person, we take their ratio divided by their ratio numerator times 72 people at the party
[U]Calculate ratios:[/U]
[LIST]
[*]Men: [URL='https://www.mathcelebrity.com/fraction.php?frac1=4%2F9&frac2=72&pl=Multiply']4/9 * 72[/URL] = [B]32[/B]
[*]Ladies: [URL='https://www.mathcelebrity.com/fraction.php?frac1=3%2F9&frac2=72&pl=Multiply']3/9 * 72[/URL] = [B]24[/B]
[*]Kids: [URL='https://www.mathcelebrity.com/fraction.php?frac1=2%2F9&frac2=72&pl=Multiply']2/9 * 72[/URL] = [B]16[/B]
[/LIST]
[U]Check our work:[/U]
Men + Ladies + Kids = 32 + 24 + 16
Men + Ladies + Kids = 72 <-- This checks out!

Cards in a pack are either orange or purple. 80% of the cards are orange. Write the ratio of orange

Cards in a pack are either orange or purple. 80% of the cards are orange. Write the ratio of orange cards to purple cards.
[URL='https://www.mathcelebrity.com/perc.php?num=+5&den=+8&num1=+16&pct1=+80&pct2=+90&den1=+80&pct=80&pcheck=4&decimal=+65.236&astart=+12&aend=+20&wp1=20&wp2=30&pl=Calculate']80% as a fraction [/URL]is 4/5.
Fractions to ratios can be written as numerator : denominator, so we have:
[B]4:5[/B]

Conjugates

Free Conjugates Calculator - Simplifies a fraction with conjugates in the denominator

difference between 2 positive numbers is 3 and the sum of their squares is 117

difference between 2 positive numbers is 3 and the sum of their squares is 117
Declare variables for each of the two numbers:
[LIST]
[*]Let the first variable be x
[*]Let the second variable be y
[/LIST]
We're given 2 equations:
[LIST=1]
[*]x - y = 3
[*]x^2 + y^2 = 117
[/LIST]
Rewrite equation (1) in terms of x by adding y to each side:
[LIST=1]
[*]x = y + 3
[*]x^2 + y^2 = 117
[/LIST]
Substitute equation (1) into equation (2) for x:
(y + 3)^2 + y^2 = 117
Evaluate and simplify:
y^2 + 3y + 3y + 9 + y^2 = 117
Combine like terms:
2y^2 + 6y + 9 = 117
Subtract 117 from each side:
2y^2 + 6y + 9 - 117 = 117 - 117
2y^2 + 6y - 108 = 0
This is a quadratic equation:
Solve the quadratic equation 2y2+6y-108 = 0
With the standard form of ax2 + bx + c, we have our a, b, and c values:
a = 2, b = 6, c = -108
Solve the quadratic equation 2y^2 + 6y - 108 = 0
The quadratic formula is denoted below:
y = -b ± sqrt(b^2 - 4ac)/2a
[U]Step 1 - calculate negative b:[/U]
-b = -(6)
-b = -6
[U]Step 2 - calculate the discriminant ?:[/U]
? = b2 - 4ac:
? = 62 - 4 x 2 x -108
? = 36 - -864
? = 900 <--- Discriminant
Since ? is greater than zero, we can expect two real and unequal roots.
[U]Step 3 - take the square root of the discriminant ?:[/U]
?? = ?(900)
?? = 30
[U]Step 4 - find numerator 1 which is -b + the square root of the Discriminant:[/U]
Numerator 1 = -b + ??
Numerator 1 = -6 + 30
Numerator 1 = 24
[U]Step 5 - find numerator 2 which is -b - the square root of the Discriminant:[/U]
Numerator 2 = -b - ??
Numerator 2 = -6 - 30
Numerator 2 = -36
[U]Step 6 - calculate your denominator which is 2a:[/U]
Denominator = 2 * a
Denominator = 2 * 2
Denominator = 4
[U]Step 7 - you have everything you need to solve. Find solutions:[/U]
Solution 1 = Numerator 1/Denominator
Solution 1 = 24/4
Solution 1 = 6
Solution 2 = Numerator 2/Denominator
Solution 2 = -36/4
Solution 2 = -9
[U]As a solution set, our answers would be:[/U]
(Solution 1, Solution 2) = (6, -9)
Since one of the solutions is not positive and the problem asks for 2 positive number, this problem has no solution

Divide 10 by the difference of z and y

[U]The difference of z and y means we subtract y from z[/U]
z - y
[U]Now, we form a fraction, where 10 is the numerator and z - y is the denominator[/U]
10/(z - y)

double v, add u, then divide t by what you have

double v, add u, then divide t by what you have
Double v means we multiply the variable v by 2:
2v
Add u:
2v + u
We build a fraction, with t as the numerator, and 2v + u as the denominator
[B]t/(2v + u)[/B]

Explain the steps you would take to find an equation for the line perpendicular to 4x - 5y = 20 and

Explain the steps you would take to find an equation for the line perpendicular to 4x - 5y = 20 and sharing the same y-intercept
Get this in slope-intercept form by adding 5y to each side:
4x - 5y + 5y = 5y + 20
Cancel the 5y's on the left side and we get:
5y + 20 = 4x
Subtract 20 from each side
5y + 20 - 20 = 4x - 20
Cancel the 20's on the left side and we get:
5y = 4x - 20
Divide each side by 5:
5y/5 = 4x/5 - 4
y = 4x/5 - 4
So we have a slope of 4/5
to find our y-intercept, we set x = 0:
y = 4(0)/5 - 4
y = 0 - 4
y = -4
If we want a line perpendicular to the line above, our slope will be the negative reciprocal:
The reciprocal of 4/5 is found by flipping the fraction making the numerator the denominator and the denominator the numerator:
m = 5/4
Next, we multiply this by -1:
-5/4
So our slope-intercept of the perpendicular line with the same y-intercept is:
[B]y = -5x/4 - 4[/B]

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!

Fraction with variable x in numerator and 6 in the denominator.

Fraction with variable x in numerator and 6 in the denominator.
The numerator is the top of the fraction.
The denominator is the bottom of the fraction.
[B]x/6[/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

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]

Help Plz

Nick's age: x
John's age: x/2
Pip's age = 2/3 * x/2 = x/3
The sum is 26, so we have:
x + x/2 + x/3 = 26
Common denominator is (1 * 2 * 3) = 6
6x/6 + 3x/6 + 2x/6 = 26
Combine like terms:
11x/6 = 26
Cross multiply:
11x = 156
x = 14.1818
This doesn't make sense for age. Are you sure you wrote out the problem right?

How to Shade Fractions

The formula is:
Numerator = One color
Denominator - Numerator = Another Color
[MEDIA=youtube]mJD2acCpol4[/MEDIA]

I only own blue blankets and red blankets. 8 out of every 15 blankets I have are red.

I only own blue blankets and red blankets. 8 out of every 15 blankets I have are red. If have i 45 blankets, how many are blue?
If 8 out of 15 blankets are red, then 15 - 8 = 7 are blue
So 7 out of every 15 blankets are blue.
Set up a proportion of blue blankets to total blankets where b is the number of blue blankets in 45 blankets
7/15 = b/45
Cross multiply:
If 2 proportions are equal, then we can do the following:
Numerator 1 * Denominator 2 = Denominator 1 * Numerator 2
15b = 45 * 7
15b = 315
To solve for b, divide each side of the equation by 15:
15b/15 = 315/15
Cancel the 15's on the left side and we get:
b = [B]21[/B]

If 2 is added to the numerator and denominator it becomes 9/10 and if 3 is subtracted from the numer

If 2 is added to the numerator and denominator it becomes 9/10 and if 3 is subtracted from the numerator and denominator it become 4/5. Find the fractions.
Convert 2 to a fraction with a denominator of 10:
20/2 = 10, so we multiply 2 by 10/10:
2*10/10 = 20/10
Add 2 to the numerator and denominator:
(n + 2)/(d + 2) = 9/10
Cross multiply and simplify:
10(n + 2) = 9(d + 2)
10n + 20 = 9d + 18
Move constants to right side by subtracting 20 from each side and subtracting 9d:
10n - 9d = -2
Subtract 3 from the numerator and denominator:
(n - 3)/(d - 3) = 4/5
Cross multiply and simplify:
5(n - 3) = 4(d - 3)
5n - 15 = 4d - 12
Move constants to right side by adding 15 to each side and subtracting 4d:
5n - 4d = 3
Build our system of equations:
[LIST=1]
[*]10n - 9d = -2
[*]5n - 4d = 3
[/LIST]
Multiply equation (2) by -2:
[LIST=1]
[*]10n - 9d = -2
[*]-10n + 8d = -6
[/LIST]
Now add equation (1) to equation (2)
(10 -10)n (-9 + 8)d = -2 - 6
The n's cancel, so we have:
-d = -8
Multiply through by -1:
d = 8
Now bring back our first equation from before, and plug in d = 8 into it to solve for n:
10n - 9d = -2
10n - 9(8) = -2
10n - 72 = -2
To solve for n, we [URL='https://www.mathcelebrity.com/1unk.php?num=10n-72%3D-2&pl=Solve']plug this equation into our search engine[/URL] and we get:
n = 7
So our fraction, n/d = [B]7/8[/B]

if 200 is divided in the ratio of 1:3:4 , what is the greatest number

if 200 is divided in the ratio of 1:3:4 , what is the greatest number
Determine the ratio denominator by adding up the ratio amounts:
1 + 3 + 4 = 8
So we have the following ratios and ratio amounts with our greatest number in bold:
[LIST]
[*]1/8 * 200 = 25
[*]3/8 * 200 = 75
[*]4/8 * 200 = [B]100[/B]
[/LIST]

If 9/20 of a salad is eaten, how much is leftover?

If 9/20 of a salad is eaten, how much is leftover?
The full salad is 1. Using a common denominator, we have 1 = 20/20
[URL='https://www.mathcelebrity.com/fraction.php?frac1=1&frac2=9%2F20&pl=Subtract']So the leftover is 20/20 - 9/20[/URL] = [B]11/20[/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.

John mows 3 lawns in 4 hours, Paul mows 5 lawns in 6 hours. Who mows faster?

John mows 3 lawns in 4 hours, Paul mows 5 lawns in 6 hours. Who mows faster?
To see who mows faster, we set up fractions with a common denominator.
You can see this by running this statement in the calculator:
[URL='https://www.mathcelebrity.com/fraction.php?frac1=3/4&frac2=5/6&pl=Compare']3/4 or 5/6[/URL]
You'll see that 5/6 is larger, so Paul mores more lawns per hour.

Kyle can walk ½ mile in ¼ of an hour. What is Kyle’s speed in miles per hour?

Kyle can walk ½ mile in ¼ of an hour. What is Kyle’s speed in miles per hour?
We write this in terms of miles per hour as:
1/2 / 1/4
We want 1 for the denominator to represent an hour, so we multiply top and bottom of the fraction by 4:
4/2 / 4/4
2 / 1
[B]2 miles per hour[/B]

Laura found a roll of fencing in her garage. She couldn't decide whether to fence in a square garden

Laura found a roll of fencing in her garage. She couldn't decide whether to fence in a square garden or a round garden with the fencing.
Laura did some calculations and found that a circular garden would give her 1380 more square feet than a square garden. How many feet of fencing were in the roll that Laura found? (Round to the nearest foot.)
Feet of fencing = n
Perimeter of square garden = n
Each side of square = n/4
Square garden's area = (n/4)^2 = n^2/16
Area of circle garden with circumference = n is:
Circumference = pi * d
n = pi * d
Divide body tissues by pi:
d = n/pi
Radius = n/2pi
Area = pi * n/2pi * n/2pi
Area = pin^2/4pi^2
Reduce by canceling pi:
n^2/4pi
n^2/4 * 3.14
n^2/12.56
The problem says that the difference between the square's area and the circle's area is equal to 1380 square feet.
Area of Circle - Area of Square = 1380
n^2/12.56 - n^2/16 = 1380
Common denominator = 200.96
(16n^2 - 12.56n^2)/200.96 = 1380
3.44n^2/200.96 = 1380
Cross multiply:
3.44n^2 = 277,324.8
n^2 = 80,617.7
n = 283.9
Nearest foot = [B]284[/B]

Leilani can read 20 pages in 2 minutes. if she can maintain this page, how many pages can she read i

Leilani can read 20 pages in 2 minutes. if she can maintain this page, how many pages can she read in an hour?
We know that 1 hour is 60 minutes.
Let p be the number of pages Leilani can read in 1 hour (60 minutes)
The read rate is constant, so we can build a proportion.
20 pages /2 minutes = p/60
We can cross multiply:
Numerator 1 * Denominator 2 = Denominator 1 * Numerator 2
[SIZE=5][B]Solving for Numerator 2 we get:[/B][/SIZE]
Numerator 2 = Numerator 1 * Denominator 2/Denominator 1
[SIZE=5][B]Evaluating and simplifying using your input values we get:[/B][/SIZE]
p = 20 * 60/ 2
p = 1200/2
p = [B]600[/B]

m=u/k-r/k for k

m=u/k-r/k for k
Multiply both sides by k to eliminate the k denominator:
km = uk/k - rk/k
Cancel the k's on the right side and we get
km = u - r
Divide each side by m:
km/m = (u - r)/m
Cancel the m on the left side:
[B]k = (u - r)/m[/B]

n + n/2 + n/4 + n/8 + n/16 = 19,375

n + n/2 + n/4 + n/8 + n/16 = 19,375
Convert to like fractions with a denominator of 16:
16n/16 + 8n/16 + 4n/16 + +2n/16 + n/16 = 19,375
31n/16 = 19,375
Cross multiply:
31n = 19,375 * 16
31n = 310000
Divide each side by 1:
31n/31 = 310000/31
n = [B]10,000[/B]

numerator of a fraction is 5 less than its denominator. if 1 is added to the numerator and to the de

numerator of a fraction is 5 less than its denominator. if 1 is added to the numerator and to the denominator the new fraction is 2/3. find the fraction.
Let n be the numerator.
Let d be the denominator.
We're given 2 equations:
[LIST=1]
[*]n = d - 5
[*](n + 1)/(d + 1) = 2/3
[/LIST]
Substitute equation (1) into equation (2) for n:
(d - 5 + 1) / (d + 1) = 2/3
(d - 4) / (d + 1) = 2/3
Cross multiply:
3(d - 4) = 2(d + 1)
To solve this equation for d, we type it in our search engine and we get:
d = 14
Substitute d = 14 into equation (1) to solve for n:
n = 14 - 5
n = 9
Therefore, our fraction n/d is:
[B]9/14[/B]

One positive number is one-fifth of another number. The difference between the two numbers is 192, f

One positive number is one-fifth of another number. The difference between the two numbers is 192, find the numbers.
Let the first number be x and the second number be y. We're given two equations:
[LIST=1]
[*]x = y/5
[*]x + y = 192
[/LIST]
Substitute equation 1 into equation 2:
y/5 + y = 192
Since 1 equals 5/5, we rewrite our equation like this:
y/5 = 5y/5 = 192
We have fractions with like denominators, so we add the numerators:
(1 + 5)y/5 = 192
6y/5 = 192
[URL='https://www.mathcelebrity.com/prop.php?num1=6y&num2=192&den1=5&den2=1&propsign=%3D&pl=Calculate+missing+proportion+value']Type this equation into our search engine[/URL], and we get:
[B]y = 160[/B]
Substitute this value into equation 1:
x = 160/5
x = [B]32[/B]

Percentage-Decimal-Fraction Relations

Free Percentage-Decimal-Fraction Relations Calculator - Calculates the relational items between a fraction, a decimal (including repeating decimal and terminating decimal), a percentage, and the numerator and denominator piece of that fraction. Also calculates the percentage change going from one number to another or the amount increase or decrease of a percentage above/below a number. Round decimals. decimals into fractions

Prove the sum of any two rational numbers is rational

Take two integers, r and s.
We can write r as a/b for integers a and b since a rational number can be written as a quotient of integers
We can write s as c/d for integers c and d since a rational number can be written as a quotient of integers
Add r and s:
r + s = a/b + c/d
With a common denominator bd, we have:
r + s = (ad + bc)/bd
Because a, b, c, and d are integers, ad + bc is an integer since rational numbers are closed under addition and multiplication.
Since b and d are non-zero integers, bd is a non-zero integer.
Since we have the quotient of 2 integers, r + s is a rational number.
[MEDIA=youtube]0ugZSICt_bQ[/MEDIA]

raise t to the 10th power, then find the quotient of the result and s

raise t to the 10th power, then find the quotient of the result and s
Raise t to the 10th power means we use t as our variable and 10 as our exponent:
t^10
The quotient means a fraction, where the numerator is t^10 and the denominator is s:
[B]t^10/s[/B]

Sergeant U has 360 rounds of ammunition to distribute to Lance Corporal (LCpl) F, Lance Corporal (LC

Sergeant U has 360 rounds of ammunition to distribute to Lance Corporal (LCpl) F, Lance Corporal (LCpl) M and Lance Corporal (LCpl) Z in the ratio 3:5:7. How many rounds did Lance Corporal (LCpl) M receive?
Our ratio denominator is:
3 + 5 + 7 = 15
Lance Corporal (LCpl) M gets 5:15 of the ammunition. [URL='https://www.mathcelebrity.com/fraction.php?frac1=5%2F15&frac2=3%2F8&pl=Simplify']Using our fraction simplifier[/URL], we see that 5/15 = 1/3
So we take 360 rounds of ammunition times 1/3:
360/3 = [B]120[/B]

Simplify 2/sqrt(5)

To do this, we need rationalize the denominator. This means get rid of the radical:
Multiply top and bottom by sqrt(5)
2sqrt(5)/sqrt(5) * sqrt(5)
sqrt(5) * sqrt(5) = sqrt(25) so we have:
2sqrt(5)/sqrt(25)
sqrt(25) = 5, so we have:
[B]2sqrt(5)/5[/B]
[MEDIA=youtube]jearVN9LhBE[/MEDIA]

Solve for x

Expand the right side:
1/3x + 1/2 = 6/4x - 10
Simplify as 6/4 is 3/2
x/3 + 1/2 = 3x/2 - 10
Common denominator of 2 and 3 is 6. So we have:
2x/6 + 1/2 = 9x/6 -10
Subtract 2x/6 from each side
7x/6 - 10 = 1/2
Add 10 to each side. 10 is 20/2
7x/6 = 21/2
Using our [URL='http://www.mathcelebrity.com/prop.php?num1=7x&num2=21&den1=6&den2=2&propsign=%3D&pl=Calculate+missing+proportion+value']proportion calculator[/URL], we get:
[B]x = 9[/B]

The denominator of a fraction is 4 more than the numerator. If 4 is added to the numerator and 7 is

The denominator of a fraction is 4 more than the numerator. If 4 is added to the numerator and 7 is added to the denominator, the value of the fraction is 1/2. Find the original fraction.
Let the original fraction be n/d.
We're given:
[LIST=1]
[*]d = n + 4
[*](n + 4) / (d + 7) = 1/2
[/LIST]
Cross multiply Equation 2:
2(n + 4) = d + 7
2n + 8 = d + 7
Now substitute equation (1) into tihs:
2n + 8 = (n + 4) + 7
2n + 8 = n + 11
[URL='https://www.mathcelebrity.com/1unk.php?num=2n%2B8%3Dn%2B11&pl=Solve']Type this equation into our search engine[/URL], and we get:
n = 3
This means from equation (1), that:
d = 3 + 4
d = 7
So our original fraction n/d = [B]3/7[/B]

The fraction has a value of 3/5. The sum of the numerator and the denominator was 40. What was the f

The fraction has a value of 3/5. The sum of the numerator and the denominator was 40. What was the fraction?
We're given two equations with a fraction with numerator (n) and denominator (d):
[LIST=1]
[*]n + d = 40
[*]n/d = 3/5
[/LIST]
Cross multiply equation 2, we get:
5n = 3d
Divide each side by 5:
5n/5 = 3d/5
n = 3d/5
Substitute this into equation 1:
3d/5 + d = 40
Multiply through both sides of the equation by 5:
5(3d/5) = 5d = 40 * 5
3d + 5d =200
To solve this equation for d, we [URL='https://www.mathcelebrity.com/1unk.php?num=3d%2B5d%3D200&pl=Solve']type it in our search engine and we get[/URL]:
d = [B]25
[/B]
Now substitute that back into equation 1:
n + 25 = 40
Using [URL='https://www.mathcelebrity.com/1unk.php?num=n%2B25%3D40&pl=Solve']our equation solver again[/URL], we get:
n = [B]15[/B]

The quotient of 49 and n squared

n squared is written as n to the power of 2, n^2
We have a fraction, where 49 is the numerator, and n^2 is the denominator
49
-----
n^2

the quotient of 77 and x

the quotient of 77 and x
Quotient means we have a fraction where 77 is the numerator and x is the denominator:
[B]77/x[/B]

the quotient of 8 and the difference of x and m

The difference of x and m means we subtract:
x - m
Quotient means a fraction. 8 is the numerator, and x - m is the denominator:
[B] 8
------
x - m[/B]

the quotient of a variable and 7

the quotient of a variable and 7.
A variable means an arbitrary number, let's call it x.
A quotient means a fraction, where x is the numerator and 7 is the denominator:
[B] x
---
7[/B]

the quotient of the cube of a number x and 5

the quotient of the cube of a number x and 5
[LIST]
[*]A number means an arbitrary variable, let's call it x
[*]The cube of a number means raise it to the 3rd power, so we have x^3
[*]Quotient means we have a fraction, so our numerator is x^3, and our denominator is 5
[/LIST]
[B]x^3
----
5[/B]

The sum of three numbers is 171. The second number is 1/2 of the first and the third is 3/4 of the f

The sum of three numbers is 171. The second number is 1/2 of the first and the third is 3/4 of the first. Find the numbers.
We have three numbers, x, y, and z.
[LIST=1]
[*]x + y + z = 171
[*]y = 1/2x
[*]z = 3/4x
[/LIST]
Substitute (2) and (3) into (1)
x + 1/2x + 3/4x = 171
Use a common denominator of 4 for each x term
4x/4 + 2x/4 + 3x/4 = 171
(4 + 2 + 3)x/4 = 171
9x/4 = 171
[URL='https://www.mathcelebrity.com/prop.php?num1=9x&num2=171&den1=4&den2=1&propsign=%3D&pl=Calculate+missing+proportion+value']Plug this equation into our search engine[/URL], and we get [B]x = 76[/B]
So y = 1/2(76) --> [B]y = 38[/B]
Then z = 3/4(76) --> [B]z = 57[/B]

The sum of x and one half of x

The sum of x and one half of x
To write this algebraic expression correctly, we have (1 + 1/2)x
To get common denominators, we write 1 as 2/2. So we have:
(2/2 + 1/2)x
[B]3/2x[/B]

What fraction lies exactly halfway between 2/3 and 3/4?

What fraction lies exactly halfway between 2/3 and 3/4?
A) 3/5
B) 5/6
C) 7/12
D) 9/16
E) 17/24
Halfway means taking the average, which is dividing the sum of the fractions by 2 for 2 fractions:
1/2(2/3 + 3/4)
1/2(2/3) + 1/2(3/4)
1/3 + 3/8
We need common denominators, so [URL='https://www.mathcelebrity.com/fraction.php?frac1=1%2F3&frac2=3%2F8&pl=Add']we type this fraction sum into our search engine[/URL] and get:
[B]17/24 - Answer E[/B]

Which of the followings can increase the value of t? (select all the apply) a. Increase the standar

Which of the followings can increase the value of t? (select all the apply)
a. Increase the standard deviation of difference scores
b. Decrease the standard deviation of difference scores
c. Increase the difference between means
d. Decrease the difference between means
[B]b. Decrease the standard deviation of difference scores
c. Increase the difference between means[/B]
[I]Increase numerator or decrease denominator of the t-value formula[/I]

Write a fraction with a denominator of 9. The fraction should be less than 1/2

Write a fraction with a denominator of 9. The fraction should be less than 1/2
Let n be the numerator. We have:
n/9 < 1/2
multiply each side by 9:
9n/9 < 9/2
n < 9/2
Examples are 8/2, 7/2, 6/2, 5/2, 4/2, 3/2,

x/y + 9 = n for x

x/y + 9 = n for x
Subtract 9 from each side to isolate the x term:
x/y + 9 - 9 = n - 9
Cancel the 9's on the left side and we get:
x/y = n - 9
Because we have a fraction on the left side, we can cross multiply the denominator y by n - 9
[B]x =[/B] [B]y(n - 9)[/B]

You have 30 DONUTS. 1/6 of them are Boston Cream. 2/5 of them are Maple. 3/10 of them are Chocolate

You have 30 DONUTS. 1/6 of them are Boston Cream. 2/5 of them are Maple. 3/10 of them are Chocolate Dip and 1/3 are Sprinkled. IS THIS EVEN POSSIBLE?? How many donuts OVER or UNDER am I? (Show your work and use EQUIVALENTS.)
We use 30 as our common denominator. Let's get [I]equivalent fraction[/I]s for each donut type with a denominator of 30:
[LIST]
[*][URL='https://www.mathcelebrity.com/equivalent-fractions.php?num=1%2F6&pl=Equivalent+Fractions']1/6[/URL] = 5/30
[*][URL='https://www.mathcelebrity.com/equivalent-fractions.php?num=2%2F5&pl=Equivalent+Fractions']2/5 [/URL]= 12/30
[*][URL='https://www.mathcelebrity.com/equivalent-fractions.php?num=3%2F10&pl=Equivalent+Fractions']3/10[/URL] = 9/30
[*][URL='https://www.mathcelebrity.com/equivalent-fractions.php?num=1%2F3&pl=Equivalent+Fractions']1/3[/URL] = 10/30
[/LIST]
Add up our numerators of the common denominator of 30:
5 + 12 + 9 + 10 = 36
So our fraction is 36/30. This makes our scenario [B]impossible[/B]. Fractions of the donut should add up to 1. Which would mean our numerators need to sum to 1 or less. Since 36 > 30, this scenario is [B]impossible.[/B]

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]