若2x=6y=3z,且xy+yz++zx=99,求2x²+12y²+9z²的值
若x/3=y/2=z/5,且xy+yz+zx=93,求9x²+12y²+2z²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/1=z/2,且xy+yz+zx=99,求zx平方+9y平方+9z平方的值?
若x:y:z=3:1:2,且zx-xy-yz=99,求2x^2+12y^2+9z^2的值
已知x+y+z=2,xy+yz+zx=-5,求x²+y²+z²的值
已知x/3=y/1=z/2,且xy+yz+zx=99,求;2X平方+12y平方+9z平方的值.
已知x/3=y/1=z/2,且xy+yz+zx=99,求2x²+12y²+9z²的值
1.已知4(xy-zx-y²+yz)=-z²+2zx-x²,求z-zy+x-3的值
已知2x-y-5z=0,x-2y+2z=0,求x²+y²+z²/xy+yz+zx的值.
若x-3=y-2=z-1,求x²+y²+z²-xy-yz-zx的值.
若x/2=y/3=z/4,求(xy+yz+zx)/(x²+y²+z²)的值.
XYZ满足XY/X+Y=-2,YZ/Y+Z=3/4,ZX/Z+X=-4/3,求XYZ/XY+YZ+ZX的值