Substitution
Below is an example of how to solve a sytem of equations using substitution.
2x + 4y = -8 y = 5x + 9 |
First you should check to see if there are variables by themselves on one side to substitute in. |
2x + 4(5x + 9) = -8 |
Substitute the y equals problem in for the y in the first problem. |
2x + 20x + 36 = -8 |
Distribute the 4 to the 5x and the 9. Then combine like terms. |
22x + 36 = -8 |
Combine the like terms. |
22x = -44 |
Get the variable alone by subtracting the 36 from both sides. |
x = -2 |
Divide both sides by 22 to get the variable alone. |