X/3=Y/2=Z/5,则分式xy+xz+yz/x^2+y^2+z^2=

分式题:xy=x+y,yz=2(y+z),zx=3(z+x),求xyz/(xy+yz+xz) 如果1=xy/x+y,2=yz/y+z,3=xz/x+z,则x的值? (2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ) 已知x+y+z=5,xy+yz+xz=7,则x^2+y^2+z^2等于? x／3=y／2＝z／5,求xy+yz+xz／x²+y²+z² 已知x:y:z=1:2:3,试求分式,x的平方+y的平方+z的平方除以xy-2yz+3xz x+3y+7z=0 2x+5y+11z=0,求(x^2+y^2+z^2)/(xy+2yz+3xz) 已知x^3+y^3-z^3=96,xyz=4,x^2+y^2+z^2-xy+xz+yz=12,则x+y-z等于 已知4x-5y+2z=0,x+4y-3z=0,求(x²+y²+z²)/xy+yz+xz x-3=y-2=z-1,求x^2+y^2+z^2-xy-yz-xz的值 已知2/x=3/y=7/z,求xy+xz+yz/x^2+y^2+z^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