x-2y=-32x+3y-z=53x+y+2z=11

试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) x/2=y/3=z/5 x+3y-z/x-3y+z 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)(x-y+z)= 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, (x+y-z)^2-(x-y+z)^2=? x,y,z为实数 且(y-z)^2+(x-y)^2+(z-x)^2=(y+z-2x)^2+(x+z-2y)^2+(x+y x,y,z为实数且(y-z)平方+(x-y)平方+(z-x)平方=(y+z-2x)平方+(z+x-2y)平方+(x+y- x+2y+3z=14 2x+y+z=7 3x+y+2z=11 3x+2y+z=9,x+y+2z=0,2x+3y-z=11 x+2y+4z=17 2x+y+z=7 3x+y+2z=11 2x+3y+z=11,3x+y-z=2,x+y+z=6求解