Question

Solve the system by substitution
2x-y+z=-4
z=5
-2x+3y-z=-10
I think the answer is (-8,-7,5)
But can someone tel me the right one and explain I’m so lost

Answer 1

2x - y + 5 = -4 ... 2x - y = -9

-2x + 3y - 5 = -10 ... -2x + 3y = -5

adding equations (to eliminate x)
... 2y = -14

Answer 2

kk is correct

Check: when (-8,-7, 5)

2x-y+z=-4

2(-8) -(-7) + 5 = -4

-16 +7+5=-4
-16+12=-4
-4=-4