y = -3x + 7
x = -2y - 16
Substitute the top expression for y in the bottom equation:
x = -2y - 16
x = -2(-3x + 7) - 16
x = 6x - 14 - 16
x = 6x - 30
-5x = -30
x = 6
Substitute back into one of the original equations:
y = -3x + 7
y = -3(6) + 7
y = -18 + 7
y = -11
Lastly, substitute back into both original equations:
y = -3x + 7 => -11 = -3(6) + 7 => -11 = -18 + 7 <--True
x = -2y - 16 => 6 = -2(-11) - 16 => 6 = 22 - 16 <--True
Answer:
x = 6
y = -11