Question 2
Show that the inequality $$
\sum_{i=1}^n \sum_{j=1}^n \sqrt{|x_i-x_j|}
\le \sum_{i=1}^n \sum_{j=1}^n \sqrt{|x_i+x_j|}
$$ holds for all real numbers $x_1$, $x_2$, …, $x_n$.
\sum_{i=1}^n \sum_{j=1}^n \sqrt{|x_i-x_j|}
\le \sum_{i=1}^n \sum_{j=1}^n \sqrt{|x_i+x_j|}
$$ holds for all real numbers $x_1$, $x_2$, …, $x_n$.