高中数学 x+y+z=1 求证（1/x+1/y+1/z)>8

已知xyz属于R+,x+y+z=1,求证x^3/(y(1-y))+y^3/(z(1-z))+z^3/(x(1-x))大于 已知x,y,z满足xyz=1,求证x^3/(x+y)+y^3/(y+z)+z^3/(z+x)大于等于3 已知x,y,z都是正数,且xyz=1,求证：x^2/(y+z)+y^2/(x+z)+z^2/(x+y)≥3/2 已知x^2+y^2+z^2=1,求证x+y+z-2xyz 已知x,y,z为非负实数,x+y+z=1,求证： 已知x+y+z=1，求证x 已知正数x.y.z满足x+y+z=1,求证：(1):(1/x-1)(1/y-1)(1/z-1)大于等于8;(2):1/x 已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/ 已知实数x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求x2/(y+z)+y2/(z+x)+z2/( {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 已知 x/(y+z)+y/(z+x)+z/(x+y)=1 x+y+z=1 求xyz/(x+y)(y+z)(z+x)的最大值