已知2/x=3/y=4/z求4x^2+2yz+z^2/x+y+z*x-y-z/8x^2+4yz+2z^2的值
已知3x-4y-z=0 2x+y-8z =0,求(x²+y²-z²)/(xy+yz)的值
已知三个数x,y,z,满足xy/x+y=-2,yz/y+z=4/3,zx/z+x=-4/3,求(xyz)/(xy+yz+
1.已知3x-4y-z=0,2x+y-8z=0.求x²+y²+z²/xy+yz+2xz 的
已知x-y=4,y-z=2,求x^2y+y^2z+z^2x-(xy^2+yz^2+zx^2)的值
已知x-y=4,y-z=2,求x^2y+y^2z+z^2x-(xy^2+yz^2+zx^2)的值.
已知3x-4y-z=0,2x+y-8z=0,求xy+yz分之x二次方+y二次方-z二次方
已知x /2=y/3=z/4,求代数式x-2y+3z/xy+2yz+3yz的值
若x/3=y=z/4,且xy+xz+yz=76,求2x*x+12y*y+9z*z的值
已知{3x-4y-z=0 求x^2+y^2+z^2/xy+yz+2zx的值 2x+y-8=0
已知xy/x+y=3,yz/y+z=2,zx/z+x=1,求y的值
已知4x-5y+2z=0,x+4y-3z=0,求(x²+y²+z²)/xy+yz+xz
已知4x-3y-3z=0,x-3y-z=0 求xy+2yz/x²+y²+z²