Solve The Problem Thread

[Tirreggregars]

I will be posting some problems, once a week, I consider hard and interesting, and anyone is free to solve them.

 

To start it off:

We take any prime number (p) that is greater than or equal to 5 (p≥5), prove that p^2-1 is divisible by 24.

Please, don't search the problems up, some of them you won't find and some you will, but it ruins the point if you do

Edited February 25, 2021 by Tirreggregars (see edit history)