Question 65
Let $x_{1}, \ldots, x_{n}$ of any reals be. Show that $$
\sum_{i=1}^{n} \sum_{j=1}^{n}\left|x_{i}+x_{j}\right| \geqslant n \sum_{i=1}^{n}\left|x_{i}\right| .
$$
\sum_{i=1}^{n} \sum_{j=1}^{n}\left|x_{i}+x_{j}\right| \geqslant n \sum_{i=1}^{n}\left|x_{i}\right| .
$$