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? (4 points)
A. x = 3x + 6
B. x + 4 = 3x + 6
C. x + 6 = 3x + 4
D.x = 3x