Question

Consider the following set of equations:

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

Answer 1

Using the substitution method, we can plug equation 1 into equation 2 (in place of x) as a result we see:
x + 4 = 3x + 6