Use Substitution to solve a + b = 88 and 13a + 17b = 128
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Use the substitution method to solve:
a + b = 88
13a + 17b = 128
Check Format
Equation 1 is in the correct format.
Check Format
Equation 2 is in the correct format.
Rearrange Equation 2 to solve for a:
13a + 17b = 128
Subtract 17b from both sides to isolate a:
13a + 17b - 17b = 128 - 17b
13a = 128 - 17b
Now divide by 13:
13a
13
=
128 - 17b
13
Revised Equation 2:
a =
128 - 17b
13
Plug Revised Equation 2 value into a:
1(a) + b = 88
1 * ((128 - 17b)/13) + b = 88
((128 - 17b)/13) + b = 88
Multiply equation 1 through by 13
13 * (((128 - 17b)/13) + b = 88)
13 * (((128 - 17b)/13) + b = 88)
128 - 17b + 13b = 1144
Group like terms:
-17b + 13b = 1144 - 128
-4b = 1016
Divide each side by -4
-4b
-4
=
1016
-4
b =
1016
-4
b = -254
Plug this answer into Equation 1
1a + 1(-254) = 88
1a - 254 = 88
1a = 88 - -254
1a = 342
Divide each side by 1
1a
1
=
342
1
a =
342
1
a = 342
What is the Answer?
a = 342 and b = -254
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.
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