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
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
急!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+XZ的值
已知x、y、z均为正实数,且xy+yz+xz=4xyz,则x/yz+y/xz+z/xy的最小值为多少?
XYZ满足XY/X+Y=-2,YZ/Y+Z=3/4,ZX/Z+X=-4/3,求XYZ/XY+YZ+ZX的值
已知xyz=1,求x/(xy+x+1)+y/(yz+y+1)+z/(xz+z+1)的值
x+y+z=1,x,y,z都是正数,求xy+yz+xz-3xyz的最大值和最小值
xy+yz+zx=1,求x√yz+y√zx+z√xy
已知实数xyz满足x+y+z=5,xy+yz+zx=3,求z的最大值
已知,xyz=0,求x/(xy+x+1)+y/(yz+y+1)+z/(xz+z+1)值?
分式题:xy=x+y,yz=2(y+z),zx=3(z+x),求xyz/(xy+yz+xz)