证明:运用公式:A^3+B^3+C^3>=3ABC
a/x+b/y+c/z>=3(a/x)^(1/3)(b/y)^(1/3)(c/z)^(1/3)
=3(abc/xyz)^(1/3)
=3(abc/abc)^(1/3)
=3
所以,a/x+b/y+c/z>=3
证明:运用公式:A^3+B^3+C^3>=3ABC
a/x+b/y+c/z>=3(a/x)^(1/3)(b/y)^(1/3)(c/z)^(1/3)
=3(abc/xyz)^(1/3)
=3(abc/abc)^(1/3)
=3
所以,a/x+b/y+c/z>=3