5x-3y+z=2(1)
5x+2y-4z=3(2)
-5x+y-z=2(3)
(1)+(3),
y=-2,
(2)+(3),
3y-5z=5
z=-11/5,
x=-9/5
所以
x=-9/5,
y=-2
z=-11/5
x+y=-2(1)
x+z=13(2)
y+z=1(3)
(1)+(2)+(3),
x+y+z=6,(4)
(4)-(3),x=5
(4)-(2),y=-7,
(4)-(1),z=8
所以
x=5,
y=-7
z=8