12x+4y+2z=-7 (1)
3x-12y+6z=-4 (2)
9x-16y+4z=-3 (3)
solve the system
just need the steps how to do it
I would go for the y's
3 times the first added to the 2nd --->
4 times the first added to the 3rd ---->
you now have two equations with only x and z
try to finish it.