# rings

• Jan 21st 2010, 06:05 AM
bookie88
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?
• Jan 21st 2010, 07:33 AM
Drexel28
Quote:

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?

$e=ee'=e'$