x/zy + y/xz + z/xy >=1/x + 1/y + 1/z 证明

证明 当x+y+z=1时,x/yz+y/xz+z/xy≥9 若x/3=y/1=z/4,且xy+xz+zy=76,求2x(2)+12y(2)+9z(2) 设x,y,z∈R+,xy+yz+xz=1,证明不等式:(xy)^2/z+(xz)^2/y+(yz)^2/x+6xyz≥x 已知:xyz=1,x+y+z=2,x^2+y^2+z^2=16求1/(xy+2z)+1/(zy+2x)+1/(xz+2y XYZ-XY-XZ+X-YZ+Y+Z-1 xyz-xy-xz+x-yz+y+z-1因式分解 x+y+z=5,xy+xz+yz=1 ,求Z的最小值和最大值 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 如果1=xy/x+y,2=yz/y+z,3=xz/x+z,则x的值? 解方程组：xy/(x+y)=1/27,yz/(y+z)=1/33,xz/(x+z)=1/30 已知xyz=1,求x/(xy+x+1)+y/(yz+y+1)+z/(xz+z+1)的值 x/(xy+x＋1)＋y/(yz+y+1)＋z/(xz+z+1)=?其中 xyz＝1