sorry if it is not very clear... the question is regarding equivalence classes congruence classes of modulo m. does that make it any clearer? i'm not too sure what the question wants me to do..
its basically asking to prove that when adding and multiplying congruent classes in modular arithmetic it does not matter about where brackets are when adding, and the order of multiplication... i think.
Thanks
Ps - in Zm i mean Zm (set of integers modulo m)