Question 286099
You are given:

(1) 7x+2y=-30
(2)  x=42-8y

Substitute (2) in (1)

7 ( 42 -8y) + 2y = -30

Distributing:
 294 - 56y + 2y = -30

Combining like-terms:

294 - 54y = -30

-54y = -324

y = 6