x：y：z=2:3:4,x+2y-z=12,求x,y,z

x+2y=3x+2z=4y+z 求x:y:z x+y/2=z+x/3=y+z/4 x+y+z=27 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 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 x+y+z=6 x+2y+3z=14 y+1=z 2x+z=10 x+y-z=4 3x-y-z=0 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 x+y+z=2 4x+2y+z=4 2x+3y+z=1 4x+y+z=-3 2x+3y-4z=-10 x+2y-z=-1 x-y-z=1 2x+y-3z=4 3x-2y-z=-1 3x-y+2z=-1 4x+y+z=5 x-2y-z=-2 x+y-z=6 x-3y+2z=1 3x+2y-z=4 阿 x+y-z=6,x-3y+2z=1,3x+2y-z=4 x+y+z=-5,3x+y+z=1,4x+3y+2z=-2快 3x+2y+z=4 x+y+z=10 2x+3y-z=1