x-y-z=1 ①2x+y-3z=4 ②3x-2y-z=-1 ③ ①+②，得3x-4z=5 ④③+②*2，得7x-7z=7, 即 4x-4z=4 ⑤ x-z=1⑤-④,得x=-1,代入z=-2代入①，得y=0所以：x=-1,y=0,z=-2
