Question

2x+3y-z=4,3x-2y+3z=7,x+3y-2z=-1

Answer 1

2x+3y-z=4 (1)

3x-2y+3z=7 (2)

x+3y-2z=-1 (3)

(1)×2+(2)×3

13x+7z=29 (4)

(1)-(3)

x+z=5 (5)

(4)-(5)×7

13x-7x=29-35

6x=-6

所以

x=-1

z=5-x=6

y=(3x+3z-7)/2=4