若x/3=y/2=z/5,且xy+yz+zx=93,求9x*x+12y*y+2z*z的值.

若x/3=y/2=z/5,且xy+yz+zx=93,求9x*x+12y*y+2z*z的值. 若|x-3|+|y+2|+|2z+1|=0,求(xy-yz)(y-x+z) 若3/x=y=z/5 且xy+yz+xz=99 求2x^2+9y^2+9z^2的值 (x+y-xy)/(x+y+2xy)=(y+z-2yz)/(y+z+3yz)=(z+x-3zx)/(z+x+4zx),且2/x=3/y=1/z,则xyz=? 已知（x+y-xy）/(x+y+2xy)=(y+z-2yz)/(y+z+3yz)=(z+x-3zx)/(z+x+4zx),且2/x=3/y-1/z,则xyz=? 若x/3=y/2=z/5,且xy+yz+zx=93,求9x²+12y²+2z²的值. 若x/3=y=z/4,且xy+xz+yz=76,求2x*x+12y*y+9z*z的值 若x,y,z都是正实数,且x^2+y^2+z^2=1,求证yz/x+xz/y+xy/z>=根号3 若Y/X=3/2,Y/Z=3/4.则2XY+YZ/2YZ-XY=多少 若Y/X=3/2,Y/Z=3/4.则(2XY+YZ)/(2YZ-XY)=多少 若x/2=1/y=z/3,且xy+xz+yz=99,求4x^2-2xz+3yz-9y^2的值. 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) 若3/x=2/y=5/z则xy+yz+zx/x^2+y^2+z^2=? 若x/3=y/2=z/5则x^2-y^2-z^2/（xy+yz+zx） 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.2.若x^2+y^2-2x-6y+10=0,求分式x^2-y^2/xy的值.请一楼回答者写出第二题具体答案！ 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 (x-3y+z)^2+/ 5x-4y+z/=0 且xyz≠0 xy+yz+zx/x^2+y^2+z^2(x-3y+z)^2+/ 5x-4y+z/=0 且xyz≠0 求：xy+yz+zx/x^2+y^2+z^2