x／3=y／2＝z／5,求xy+yz+xz／x²+y²+z²

分式题:xy=x+y,yz=2(y+z),zx=3(z+x),求xyz/(xy+yz+xz)xy=x+y,yz=2(y+z),zx=3(z+x),求xyz/(xy+yz+xz) x／3=y／2＝z／5,求xy+yz+xz／x²+y²+z² 若|x-3|+|y+2|+|2z+1|=0,求(xy-yz)(y-x+z) 已知1/x=5/y+z=3/z+x 求2xy/yz ÷x/Y的值 已知XY=2(X+Y),YZ=4(Y+Z),ZX=5(Z+X),求X,Y,Z已知XY=2(X+Y),YZ=4(Y+Z),ZX=5(Z+X),求X,Y,Z 方程组xy/x+y=2 yz/y+z=4 zx/x+z=5 求x,y,z x/3=y/4=z/5 求xy+yz+zx/x^2+y^2+z^2的值 xy:yz:zx=2:3:5 求x:y:z |x-3|+|y+2|+|2z+|=0,求(xy-yz)(y-x+2的值 X+Y+Z=5,XY+XZ+YZ=3求Z范围 若|x-3|+|y+z|+|2z+1|=0,求XY-YZ的值 若｜x-3｜+｜y+z｜+｜2z+1｜=0,求xy-yz的值 已知x+y+yz=5,y+z+xy=8,x+z+xy=9,求x,y,z 若实数x,y,z满足x+y+z=5,xy+yz+xz=3,求z的最大值 实数x,y,z满足x+y+z=5,xy+yz+zx=3,求z的最大值 时数x,y,z满足x+y+z=5,xy+yz+zx=3,求Z最大值 x+3y+7z=0 2x+5y+11z=0,求(x^2+y^2+z^2)/(xy+2yz+3xz) 若x/3=y/2=z/5,且xy+yz+zx=93,求9x*x+12y*y+2z*z的值.