x/3=y/2=z/5,求xy+yz+xz/x²+y²+z²
x/3=y/2=z/5,求xy+yz+xz/x²+y²+z²
已知4x-5y+2z=0,x+4y-3z=0,求(x²+y²+z²)/xy+yz+xz
已知x/3=y/4=z/6,求(xy+yz+xz)/(x²+y²+z²)
已知x+y+z=1,x²+y²+z²=2求xy+yz+xz的值
已知x-y=1/2+√3,y-z=1/2-√3,求x²+y²+z²-xy-xz-yz的值
已知x+y+z=10,xy+xz+yz=8,求x²+y²+z²的值
X+Y+Z=5,XY+XZ+YZ=3求Z范围
已知x/3=y分/4=z/5≠0求(3x²+4y²+5z²)/(xy+xz+yz)的值,
已知x:y:z=1:2:3,xy+yz+xz=66,求2x²+12y²-9z²的值.
若实数x,y,z满足x+y+z=5,xy+yz+xz=3,求z的最大值
(2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ)
xy/x+y=1,yz/y+z=2,xz/x+z=3求x,y