To solve a system of equations with the addition method, follow these steps:
1. Rewrite both equations in standard form if they aren’t in it already.
2. Choose one of the variables to get onto the same side of the equation in both equations.
3. Multiply the terms of the equations by some constant that will cause the variable you chose in step 2 to have the same coefficient in both equations, but with opposite signs (ie: and . Both have , but one of them has the opposite sign).
4. Add the equations together. The variables that have the opposite sign of each other should cancel out, leaving you with one variable.
5. Solve the new equation for this variable.
6. Substitute the value you got in step 4 back into either one of the original equations, and solve for the remaining variable.
7. Plug both values back into the original equations and check the solutions.