已知xyz=1,求x/(xy+x+1)+y/(yz+y+1)+z/(xz+z+1)的值
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?
已知xyz=1,试求(1/xy+x+1)+(1/yz+y+1)+(1/xz+z+1)的值
XYZ-XY-XZ+X-YZ+Y+Z-1
xyz-xy-xz+x-yz+y+z-1因式分解
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x+y+z=3,xy+yz+xz=-1,xyz=2,求x^2y^2+y^2z^2+x^2z^2
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
已知正数x,y,z满足x+y+z=xyz,求1/根号(xy)+1/根号(yz)+2/根号(xz)的最大值.
已知x+y+z=1,x²+y²+z²=2求xy+yz+xz的值
已知x+y+z=1,xy+yz+xz=0,求x^2+y^2+z^2的值.
1/x+1/y=1/2,1/y+1/z=1/3,1/x+1/z=1/6,求xyz/(xy+yz+xz)的值