{x-y+2z=3 2x+3y-z=4 3x+2y+4z=2
问题描述：
{x-y+2z=3 2x+3y-z=4 3x+2y+4z=2
答
x-y+2z=3 (1)
2x+3y-z=4 (2)
3x+2y+4z=2 (3)
(1)×3+(2)
5x+5z=13 (4)
x+z=13/5 (5)
(1)×2+(2)
5x+8z=8 (6)
(6)-(4)
3z=-5
z=-5/3
x=13/5-z=64/15
y=x+2z-3=-31/15