Question

2x-2y-4z=2
-x+y+z=2
x-2y+z=-2

Answer 1

1) 2x-2y-4z=2
2) -x+y+z=2
3) x-2y+z=-2 

isolando x na eq 2) -x+y+z=2  -> x=y+z-2

substituindo na eq 3 e isolando y
y+z-2-2y+z=-2
-y+2z=0
y=2z

substituindo na eq 1)
2x-2y-4z=2
2(y+z-2)-2(2z)-4z=2
2(2z+z-2)-4z-4z=2
6z-4-8z=2
-2z=6
z=-3

y = 2z = -6

x = y + z -2 = -11

x=-11, y=-6 e z=-3