Answer:
To solve the system of equations by substitution:
2x+y=-2
3x-y=7
first solve for y:
2x+y=-2
y=-2x-2
Then plug ^^ equation for y in the other equation
3x-(-2x-2)=7
5x+2=7
5x=5
x=1
Then solve for y:
2(1)+y=-2
y=-4
Final answer is x = 1 and y = -4
Hope it helps!