x+2y+z=12 3x-y+z=6 x+y+z=12是个三元一次方程组,求它的解!各位哥哥姐姐都帮帮我吧,明天交作业啊!

如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 3x-y+z=4,2z+3y-z=12,x+y+z=6的解 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) X=3z X+y+z=12 X+2y-2z=10 x+y+z=6 x+2y+3z=14 y+1=z 3x-y+z=3,2x+3y-z=12,x+y+z=6解方程组 解方程组{3x+y-z=4,2x-y+3z=12,x+y+z=6} 解方程组2x+3y-z=12,3x-y+z=4,x+y+z=6 {3x-y+z=4,2x+3y-z=12,x+y+z=6 3x-y+z=4,2x+3y-z=12,x+y+z=6 3x - y + Z=4{ 2x + 3y - Z=12X + Y + Z = 6 3x-y+z=4, 2x+3y-z=12, x+y+z=6 3x-y+z=4 2x+3y-z=12 x+y+z=6 2x+3y-z=12 3x-y+z=4 x+y+z=6 方程组 3X-Y+Z=10 X+2Y-Z=6 X+Y+Z=12 三元一次方程组,1.x-2y+z=9 2x+y+3z=10 3x+2y1.x-2y+z=92x+y+3z=103x+2y-z2.3x-5y+2z=14x+5y-z=5X-5y+3z=-23.7x+2y-z=76x-y+z=74x+3y+z=94.4x+3y-2z=-75x-6y+z=12x+z=-25.2x+3y-4z=-23x-2y+5z=262x+5z=31 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少,