# Math Help - rings

1. ## rings

assume R is a ring with unity e. Prove: if a is in R has a multiplicative inverse, the multiplicative inverse of a is unique.

so if ax=xa=e is the multiplicative inverse, the to make it unique, how do you show that?

2. Originally Posted by bookie88
assume R is a ring with unity e. Prove: if a is in R has a multiplicative inverse, the multiplicative inverse of a is unique.

so if ax=xa=e is the multiplicative inverse, the to make it unique, how do you show that?
$e=ee'=e'$