Can someone please give me an example of of this definition, as I am finding it hard to get my head around or even understand what an "associate" is.
Let $R$ be a commutative ring with unity. Elements $a$ and $b$ are called associates in $R$ if $b =ua$ for some unit $u$ of $R$.
My notes don't provide an example. Can someone please explain it further or even better show me an example of this definition?