Solve the top equation for x
2x-2y=20
Divide everything by 2
x-y=-10
Get x by itself
x=-10+y
Then plug x into the other equation
-2(-10+y)+4(-10+y)=14
Solve new equation and you get y=-3
Plug y back into either equation
-2x+4(-3)=14
Solve and you get x=-13
So your answer will be
(x,y) = (-13,-3)
