解:依题意得方程组,
x-y-z=1 (1)
2x+y-3z=4 (2)
3x-2y-z=-1 (3)
由(1)得
y+1=x-z
y=x-z-1
将y=x-z-1带入(2)得
2x+(x-z-1)-3z=4
2x+x-z-1-3z=4
3x-4z-1=4
3x-4z=5 (4)
将y=x-z-1带入(3)得
3x-2×(x-z-1)-z=-1
3x-2x+2z+2-z=-1
x+z+2=-1
x+z=-3 (5)
(4)+(5)×4得
3x-4z+(x+z)×4=5+(-3)×4
3x-4z+4x+4z=5-12
7x=-7
x=-1
将x=-1带入(5)得
-1+z=-3
z=-2
y=x-z-1=-1-(-2)-1=-1+2-1=0
即x=-1,y=0,z=-2