Use the substitution method to solve:
3x - 8y = 20
7x + 2y = 57
Check Format
Equation 1 is in the correct format.
Check Format
Equation 2 is in the correct format.
Rearrange Equation 2 to solve for x:
7x + 2y = 57
Subtract 2y from both sides to isolate x:
7x + 2y - 2y = 57 - 2y
7x = 57 - 2y
Now divide by 7:
Revised Equation 2:
| x = | 57 - 2y |
| 7 |
Plug Revised Equation 2 value into x:
3(x) - 8y = 20
3 * ((57 - 2y)/7) - 8y = 20
((171 - 6y)/7) - 8y = 20
Multiply equation 1 through by 7
7 * (((171 - 6y)/7) - 8y = 20)
7 * (((171 - 6y)/7) - 8y = 20)
171 - 6y - 56y = 140
Group like terms:
-6y - 56y = 140 - 171
-62y = -31
Divide each side by -62
| y = | -31 |
| -62 |
y = 0.5
Plug this answer into Equation 1
3x - 8(0.5) = 20
3x - 4 = 20
3x = 20 - -4
3x = 24
Divide each side by 3
| x = | 24 |
| 3 |
x = 8
What is the Answer?
x = 8 and y = 0.5
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?
What 7 concepts are covered in the Simultaneous Equations Calculator?
- cramers rule
- an explicit formula for the solution of a system of linear equations with as many equations as unknowns
- eliminate
- to remove, to get rid of or put an end to
- equation
- a statement declaring two mathematical expressions are equal
- simultaneous equations
- two or more algebraic equations that share variables
- substitute
- to put in the place of another. To replace one value with another
- unknown
- a number or value we do not know
- variable
- Alphabetic character representing a number
