x:y=1:3,y:z=1:4,且x-2y+3z=62,求多项式xy-yz=xz的值

已知x:y=1:3,y:z=1:4,且x-2y+3z=62,多项式xy-yz+xz的值为 若x/2=1/y=z/3,且xy+xz+yz=99,求4x^2-2xz+3yz-9y^2的值. 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 若x/3=y=z/4,且xy+xz+yz=76,求2x*x+12y*y+9z*z的值 x-3=y-2=z-1,求x^2+y^2+z^2-xy-yz-xz的值 若X/3=Y/1=Z/4,且XY+XZ+YZ=76,求2X^2+12Y^2+9Z^2的值 若x/3=y/1=z/4,且xy+xz+yz=76,求2x²+12y²+9z²的值 已知1=xy/x+y,2=yz/y+z,3=xz/x+z,求x+y+z的值 已知xy分之x+y=3,yz分之y+z=2,xz分之x+z=1,求x,y,z的值 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 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 急!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