Question

Solve the system of equations by any method.

11x + 8y = -16
x=4y + 10

A. (4, 7 1/2)
B. (4, -1 1/2)
C. (4/9, -2 7/8)
D. (4/13, -2 11/26)

Answer 1

I'll use substitution. I think that's the easiest.

11x + 8y = -16
x = 4y + 10

Plug in: 11(4y + 10) + 8y = -16

Simplify: 44y + 110 + 8y = -16

Simplify: 52y + 110 = -16

Subtract from both sides: 52y = -16 - 110

Simplify: 52y = -126

Divide: y = -126/52

Simplify: -2.42 or -2 and 11/26'

I could continue to solve for x, but we can see your options and D is the only one with this value for y.