若x:y:z=3:1:2,且zx-xy-yz=99,求2x^2+12y^2+9z^2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? (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/1=z/2,且xy+yz+zx=99,那麽2x^2+12y^2+9z^2=? 若x/3=y/1=z/2,且xy+yz+zx=99,则2x^2+12y^2+9z^2= 若x:y:z=3:1:2,且zx-xy-yz=99,求2x^2+12y^2+9z^2的值 若x/3=y/2=z/5,且xy+yz+zx=93,求9x*x+12y*y+2z*z的值. 已知x,y,z为实数.(1)试比较xy+yz+zx与x^2+y^2+z^2的大小?已知x,y,z为实数.(1)试比较xy+yz+zx与x^2+y^2+z^2的大小?（2）若xy+yz+zx=75,当x^2+y^2+z^2取最小值时,求x,y,z的值?（3）若x,y,z为正实数,且xy+yz+zx=75,求x+y+z 已知X,Y,Z都是整数且xy+yz+zx=1,求证x+y+z>=根号3 已知x,y,z∈R+,且x+y+z=3,求证：x^2/（y^2+z^2+yz）+y^2/(x^2+z^2+zx）+z^2/(x^2+y^2+xy)≥1 若2x=6y=3z,且xy+yz+zx=99,求2x^2+12y^2+9z^2的值 若x/3=y/2=z/5,且xy+yz+zx=93,求9x²+12y²+2z²的值. 若2x=6y=3z,且xy+yz++zx=99,求2x²+12y²+9z²的值 已知x:y:z=3:1:2,且xy+yz+zx=99,求x^2-2y^2+3z^2的值 如果x/3=y/1=z/2,且xy+yz+zx=99,则x+2 y-3z的值为? 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 (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=?看清楚是2/x=3/y-1/z