Given the ring $ \mathbb{Z}/n\mathbb{Z} $ is always true that $ \mathbb{Z}/n\mathbb{Z}=[\text{zero divisors}]\cup[\text{units}] $
How can evaluate the zero divisors and units ?
I believe that $ a x=0 \pmod n $ for zero divisor
and $ ax=1 \pmod n $ for units
I know how to solve a congruence but what is $a$ ?? thanks.
What are the generators of the group $ \mathbb{Z}/n\mathbb{Z} $ under the addition '+' and product '$\times$'?