解方程组2x+y+x=10 x+2y+z=-6 x+y+2z=82x+y+x=10 x+2y+z=-6x+y+2z=82x+y+z=10x+2y+z=-6x+y+2z=8前三个方程不算了，下面三个是正确的

Question

解方程组2x+y+x=10 x+2y+z=-6 x+y+2z=8
2x+y+x=10
x+2y+z=-6
x+y+2z=8
2x+y+z=10
x+2y+z=-6
x+y+2z=8
前三个方程不算了，下面三个是正确的

Answer 1

2x+y+x=10 (1)
x+2y+z=-6 (2)
x+y+2z=8 (3)
(1)+(2)+(3)
4x+4y+4z=12
x+y+z=3 (4)
(1)-(4),x=7
(2)-(4),y=-9
(3)-(4),z=5