2x+3y+z=7 x-y+2x=-3 x+2y-z=6怎么解

试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, x/2=y/3=z/5 x+3y-z/x-3y+z 解方程：{2x+3y+z=7,x+y+z=4,3x+y-z=-4 解方程组{3x+y-z=4,2x-y+3z=12,x+y+z=6} 解方程{3x -y+z=4 2x+3y-z=12 x+y+z=6 解三元一次方程：x+y-z=0,2x+y+z=7,x-3y+z=8 解方程组：x+y+z=4,x+y+2z=5,3x+y-z=6 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? 5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y