已知1/x+1/y=1/6,1/y+1/z=1/9,1/z+1/x=1/15,求xyz/(xy+yz+zx)的值
分解因式:xyz-yz-zx-xy+x+y+z-1
xy+yz+zx=1,求x√yz+y√zx+z√xy
已知xy/x+y=3,yz/y+z=2,zx/z+x=1,求y的值
已知x,y,z都是正数,且xyz=1,求证:xy(x+y)+yz(y+z)+zx(z+x)》6
设xyz=1,求x/(xy+x+1)+y/(yz+y+1)+z/(zx+z+1)的值
已知1/x+1/y=1/6,1/y+1/z=1/9,1/z+1/x=1/15,求xyz/(xy+yz+zx)的值
已知xy:yz:zx=3:2:1,求①x:y:z ②x/yz:y/zx
已知xy:yz:zx=3:2:1,求(x+y):z的值
已知2x+2y+xy=-2,2y+2z+yz=-1,2z+2x+zx=50,求xyz+2(xy+yz+zx)+4(x+y
xy+yz+zx=1,x,y,z>=0
1.x,y,z为实数,且xy/x+y=1/3,yz/y+z=1/4,xz/x+z=1/5,求xyz/xy+yz+zx的值
x,y,z为实数,且xy/x+y=1/3,yz/y+z=1/4,xz/x+z=1/5,求xyz/xy+yz+zx的值