Question

Which ordered pair is a solution of the system?

x + 4y = 19
y = -2x - 4

A. (3,4)
B. (7,3)
C. (-5,6)
D. (-2,0)

Answer 1

y = -2x - 4

x + 4y = 19
x + 4(-2x - 4) = 19
x + (-8x) - 16 = 19
-7x - 16 = 19
-7x = 35
-x = 5
x = -5

y = -2x - 4
y = -2(-5) - 4
y = 10 -4
y = 6

Solution set {-5, 6} (C)