Equation M: y = x + 4

Equation P: y = 3x + 6

Which of the following is a step that can be used to find the solution to the set of equations?

x = 3x + 6

x + 4 = 3x + 6

x + 6 = 3x + 4

x = 3x

Solve the system

y = x + 4

y = 3x + 6

Note that both equations have been solved for y. Thus, you can set y = y, or

x+4=3x+6. Simplifying, - 2 = 2x, or x = - 1.

Another way to look at this would be x + 4 = 3x + 6.