Solve the system of equations by substitution.

3x + 4y = 31

2x - 4y = - 6

A. (4, 5)

B. (5, 4)

C. (-5, 12.5)

D. (5, - 4)

The correct answer is B. (5,4).

If you combine the like terms of both equations you get 5x=25

Divide both sides by 5 to isolate the variable.

x=5, plug 5 into the top equation.

3 (5) + 4y=31

15+4y=31

4y=16

y=4

x=5 y=4