IMO 2021 Shortlist A4

Show that for all real numbers x1,...,xn the following inequality holds: n ÿ i“1 n ÿ j“1 b |xi ´xj|ď n ÿ i“1 n ÿ j“1 b |...

IMO 2021 Shortlist A4

Category: Algebra

Problem

Show that for all real numbers x1,...,xn the following inequality holds: n ÿ i“1 n ÿ j“1 b |xi ´xj|ď n ÿ i“1 n ÿ j“1 b |xi `xj|.