X-4z=13

5x-4y+z=-7
-5x-5y+2z=22

x = 4z+13

5(4z+13) - 4y + z = -7
-5(4z+13) - 5y + 2z = 22

-4y + 21z = -72
-5y - 18z = 87

-24y + 126z = -432
-35y - 126z = 609

-59y = 177
y = -3
z = -4
x = -3