All right I REALLY need help. I've asked a bunch of people and just don't get it.

I understand equivalence relations. They seem easy enough, I can deal with them.

But here's a problem I really need help with:

a,b elements_of Z

aRb IFF a%n = b%n = 0

How do i get an equivalence class for this, I'm in desperate need of help!

Thank you.

and PS I've worked out a few pages of attempts, and the mostly end up with a = a