x+2y+3z=14 3x+y+2z=11 2x+3y+z=11答案,
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
x+2y+3z=14 2x+y+z=7 3x+y+2z=11
x+2y+3z=14 2x+y+z=7 3x+y+2z=11 求x y z
x/2=y/3=z/5 x+3y-z/x-3y+z
3x+2y+z=9,x+y+2z=0,2x+3y-z=11
2x+3y+z=11,3x+y-z=2,x+y+z=6求解
3x-y+z=3 2x+y-3z=11 x+y+z=12 解方程
x+2y+4z=17 2x+y+z=7 3x+y+2z=11
解方程组{2x+3y+z=11,x+y+z=0,3x-y+z=-2.
设x+y+z=11求函数u=2x*x+3y*y+z*z的最小值
x+2y+3z=14 3x+y+2z=11 2x+3y+z=11答案,
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