Question

3x + y - z= -6
2x - y + 2z = 8
4x + y - 3z = -21

Answer 1

x=-1

y=4

z=7

Explanation:

3x + y - z= -6(1)

2x - y + 2z = 8(2)

4x + y - 3z = -21(3)

(1)+(2): 5x+z=2(4)

(2)+(3): 6x-z=-13(5)

(4)+(5): 11x=-11

x=-1

so z=2-5x=7

y=-6-3x+z=4