Answer:
d
Step-by-step explanation:
Substitute x = -1 into the equations. If the solution is y = 4 for both, then (-1, 4) is the solution.
(a) y = 1 + 3 = 4
y = -1 + 1 = 0
(b) -1 - y = 2 ⇒ y = -3
-1 + y = -6 ⇒ y = -5
(c) -1 + y = -2 ⇒ y = -1
7(-1) - 4y = 8 ⇒ y = -15/4
(d) y = 1 + 3 = 4
y = 2(-1) = 6 = 4
