解三元一次方程组 1.{2x-y+z=1,3x+y-2z=2,x+2y-z=3 2.{3x-y+z=4,2x+3y-z=12,x+y+z=63.{3x-y+z=4,2x+3y-z=12,x+y+z=6 4.{a+b+c=12,2a+b-c=3,a-b+c=25.{x-4y+z=-3,2x+y-z=18,x-y-z=7 6.{4x+3y+2y=7,6x-4y-z=6,2x-y+z=17,{x+y+2z=6,y-x+z=1,x+2y=0 问题有点多请多多包涵,
问题描述：
解三元一次方程组 1.{2x-y+z=1,3x+y-2z=2,x+2y-z=3 2.{3x-y+z=4,2x+3y-z=12,x+y+z=6
3.{3x-y+z=4,2x+3y-z=12,x+y+z=6 4.{a+b+c=12,2a+b-c=3,a-b+c=2
5.{x-4y+z=-3,2x+y-z=18,x-y-z=7 6.{4x+3y+2y=7,6x-4y-z=6,2x-y+z=1
7,{x+y+2z=6,y-x+z=1,x+2y=0 问题有点多请多多包涵,
答
解的格式（x y z）
3.(2 3 1) 4.(5/3 5 16/3)
5.(7 2 -2) 6.(7/6 7/15 -13/15)
7.(8/7 -4/7 19/7)