Answer:
x = -3
Step-by-step explanation:
y = -x + 2
7x + 4y = -1
Subsitution method: (Substitute y)
7x + 4(-x+2) = -1
Expand.
7x + (-4x + 8) = -1
One plus and one minus make one minus. Two plus makes a plus.
7x -4x + 8 = -1
Simplify.
3x + 8 = -1
Isolate 3x.
3x = -1-8
= -9
Find x.
x = -9 ÷ 3
= -3
