Use Substitution to solve 12f + 8i = 260 and 15f + 6i = 240
Crop Image
Use the substitution method to solve:
12f + 8i = 260
15f + 6i = 240
Check Format
Equation 1 is in the correct format.
Check Format
Equation 2 is in the correct format.
Rearrange Equation 2 to solve for f:
15f + 6i = 240
Subtract 6i from both sides to isolate f:
15f + 6i - 6i = 240 - 6i
15f = 240 - 6i
Now divide by 15:
15f
15
=
240 - 6i
15
Revised Equation 2:
f =
240 - 6i
15
Plug Revised Equation 2 value into f:
12(f) + 8i = 260
12 * ((240 - 6i)/15) + 8i = 260
((2880 - 72i)/15) + 8i = 260
Multiply equation 1 through by 15
15 * (((2880 - 72i)/15) + 8i = 260)
15 * (((2880 - 72i)/15) + 8i = 260)
2880 - 72i + 120i = 3900
Group like terms:
-72i + 120i = 3900 - 2880
48i = 1020
Divide each side by 48
48i
48
=
1020
48
i =
1020
48
i = 21.25
Plug this answer into Equation 1
12f + 8(21.25) = 260
12f + 170 = 260
12f = 260 - 170
12f = 90
Divide each side by 12
12f
12
=
90
12
f =
90
12
f = 7.5
What is the Answer?
f = 7.5 and i = 21.25
How does the Simultaneous Equations Calculator work?
Free Simultaneous Equations Calculator - Solves a system of simultaneous equations with 2 unknowns using the following 3 methods: 1) Substitution Method (Direct Substitution) 2) Elimination Method 3) Cramers Method or Cramers Rule
Pick any 3 of the methods to solve the systems of equations
2 equations 2 unknowns This calculator has 2 inputs.
What 1 formula is used for the Simultaneous Equations Calculator?