已知x+2z-3y=0,求x²-9y²+4z²+4zx
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.
已知x/2=y/3=z/4,求x²+2y²+3z²/xy+yz-zx
已知x+y+z=2,xy+yz+zx=-5,求x²+y²+z²的值
已知x+y+z=1,x²+y²+z²=2求xy+yz+zx
已知{3x-4y-z=0 求x^2+y^2+z^2/xy+yz+2zx的值 2x+y-8=0
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+
已知x²+y²+z²-2x+4y-6z+14=0,求x+y-z/x+y+z的值
已知2x-3y-z=0,x+3y-14z=0,且x,y,z不全为0,求4x的平方-5xy+z的平方/xy+yz+zx的值
若x/2=y/3=z/4,求(xy+yz+zx)/(x²+y²+z²)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x-y=4,y-z=2,求x^2y+y^2z+z^2x-(xy^2+yz^2+zx^2)的值.