1) Show that (mod p) when p is an odd prime
2) Show that if p is a prime and p > 3, then (mod p)
For 1), I really don't understand which theorem or identity I'm supposed to put into use to prove this. Obviously it works every time I just don't understand how this works in terms of technicality.
2) is the same story. I don't see how it works and therefore I can't prove it formally.