已知x+y+z=5 xy+zy+zx=3求x的取值范围
1.已知4(xy-zx-y²+yz)=-z²+2zx-x²,求z-zy+x-3的值
已知x,y,z是实数,且x+y+z=5,xy+yz+zx=3,求z的取值范围
已知实数x,y,z满足x+y+z=5,xy+yz+zx=3.求z的取值范围
怎么算3X+2Y+Z已知;XY/X+Y=1 ZY/Z+Y=2 ZX/Z+X=3 求3X+2Y+Z的值"/"是分数线或是说
已知x,y,z为实数,且x+y+z=5,xy+yz+zx=3,则z的取值范围为 ______.
实数xyz满足x+y+z=5,xy+xz+zx=3.求Z的取值范围
1.已知X,Y,Z为实数,且X+Y+Z=5,XY+YZ+ZX=3,则Z得取值范围为?
已知xy/x+y=3,yz/y+z=2,zx/z+x=1,求y的值
x2+y2+z2=xy+yz+zx求〔x-zy+z〕的2010次方的值
已知x+y+z=2,xy+yz+zx=-5,求x²+y²+z²的值
已知x+y+z=5,xy+yz+zx=9,求x^2+y^2+z^2的值
已知xy:yz:zx=3:2:1,求(x+y):z的值