(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Prove that a^{5}[tex]\equiv[/tex]a (mod 15) for every integer a.

2. Relevant equations

3. The attempt at a solution

I do not know how to show a^{5}-a is divisible by 15

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Prove a^5 congruent to a (mod 15)

**Physics Forums | Science Articles, Homework Help, Discussion**