![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
Cho các số dương $a,b,c$ và số $n \in \mathbb{N}^{*}$$.$ Chứng minh rằng $:$
$$\frac{a^{n}}{(b+c)^{n}}+\frac{b^{n}}{(c+a)^{n}}+\frac{c^{n}}{(a+b)^{n}} \geq \frac{3}{2^{n}}$$
$$\frac{a^{n}}{(b+c)^{n}}+\frac{b^{n}}{(c+a)^{n}}+\frac{c^{n}}{(a+b)^{n}} \geq \frac{3}{2^{n}}$$