x-2y+z=9 (1)
2x+y+3z=10 (2)
3x+2y-4z=-3 (3)
(2)*2+(1)
5x+7z=29 (4)
(1)+(3)
4x-3z=6 (5)
(4)*4-(5)*5
43z=86
z=2
把z=2代入(5)
4x-6=6
x=3
把x=3,z=2代入(2)
6+y+6=10
y=-2
x=3,y=-2,z=2
x-2y+z=9 (1)
2x+y+3z=10 (2)
3x+2y-4z=-3 (3)
(2)*2+(1)
5x+7z=29 (4)
(1)+(3)
4x-3z=6 (5)
(4)*4-(5)*5
43z=86
z=2
把z=2代入(5)
4x-6=6
x=3
把x=3,z=2代入(2)
6+y+6=10
y=-2
x=3,y=-2,z=2