Respuesta :

redfirearne
 8x - 6y + 4z = -58
-8x -   y + 3z =  23
      -7y + 7z = -35
7 (z-y) = -35
z - y = -5
z = y - 5
4x - 3y + 2y - 10 = -29
6x + 2y - y + 5 = -16

4x -  y = -19
6x + y = -21

10x = -40

x = -4
y = 3
z = -2

Thank you very much.
(Took me too long...)