{x+y+z=12 2x+3y-4z=2 x-3y+z=4 解方程组 要快!最好是分钟以内

x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, x+2y=3x+2z=4y+z 求x:y:z x+y/2=z+x/3=y+z/4 x+y+z=27 3x-y+z=4,2z+3y-z=12,x+y+z=6的解 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z X=3z X+y+z=12 X+2y-2z=10 2x+z=10 x+y-z=4 3x-y-z=0 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 x：y：z=2:3:4,x+2y-z=12,求x,y,z x-4y+z=-3 2x-y+z=18 x-y-z=12