x+9+z=100 3x+2y+0.5z=100 2x=y
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
3x+2y+z=9,x+y+2z=0,2x+3y-z=11
{x+y+z=6,2x-y+z=3,3x+9y+z=24
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
(x+y-z)^2-(x-y+z)^2=?
(x+y-z)(x-y+z)=
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+z)/9=(2x+y+3z)/10=-(3x+2y-4z)/3=1 连等,求x,y,z,