You need to solve a system of equations. You decide to use the elimination
method. Which of these is not allowed?

The step that is not allowed is (b) add the left side of equation 2 to the left side of equation 1
The system of equations is given as:
2x - 3y = 12
-2x + y = 8
This means that the step that is not allowed is (b)
Read more about elimination method at:
https://brainly.com/question/12691830
#SPJ1