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)
3x + 4y = 31
2x - 4y= -6
A(4, 5)
B(5, 4)
C(-5, 12.5)
D(5, -4)