已知xyz=1,求x/﹙xy+x+1﹚+y/﹙yz+y+1﹚+z/﹙xz+z+1﹚
已知xyz=1,求x/﹙xy+x+1﹚+y/﹙yz+y+1﹚+z/﹙xz+z+1﹚
x/(xy+x+1)+y/(yz+y+1)+z/(xz+z+1)=?其中 xyz=1
xy/x+y=1,yz/y+z=2,xz/x+z=3求x,y
已知xyz=1,求x/(xy+x+1)+y/(yz+y+1)+z/(xz+z+1)的值
已知,xyz=0,求x/(xy+x+1)+y/(yz+y+1)+z/(xz+z+1)值?
XYZ-XY-XZ+X-YZ+Y+Z-1
xyz-xy-xz+x-yz+y+z-1因式分解
已知x+y+z=1 求证yz/x+xz/y+xy/z的最小值为1
已知x+y+z=3,xy+yz+xz=-1,xyz=2,求x^2y^2+y^2z^2+x^2z^2
已知2x-3y+z=0 3y-2y=6z 且xyz≠0求xy+yz+xz分之x²+y²+z²
x+y+z=1,x,y,z都是正数,求xy+yz+xz-3xyz的最大值和最小值
已知xyz=1,试求(1/xy+x+1)+(1/yz+y+1)+(1/xz+z+1)的值