3X+Y+Z=0,2X-Y+3Z=1,X+2Y-Z=4

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,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, {x+y+z=4 {2y+z=0 {3x+2y-4z=-1 若x-2y+4z=1,x+3y-7z=0,则y:z=? x/2=y/3=z/5 x+3y-z/x-3y+z 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 2x-2y+z=0 2x+y-z=1 x+3y-2z=1 x-3y+z=0,3x-2y-4z=0,则x:y:z=多少? x+y+z=4 x-2y+z=-2 x+2y+3z=0求解 已知{x-3y+2z=0 3x-3y-4z+0,则x:y:z=? x+y+z=2 4x+2y+z=4 2x+3y+z=1