Answer:-2
Explanation:
-y+2x=-1 needs to be changed to y=-2x-1 so that you can set the two equation equal to each other in order to solve for x. That makes it -2x-1=1/2x+4
-4= -4
-2x-5 = 1/2x
+2x = +2x
-5 = 2.5x
div. 2.5 div. 2.5
X= -2
Check: y= -2(-2)-1 Y=3
y=1/2(-2)+4 Y=3