I am trying to prove this statement about divisibility: $mn|a$ implies $m|a$ and $n|a$.
I cannot start the proof. I need to prove either the right or left side. I don't know how to use divisibility theorems here. Generally, I have problems in proving mathematical statements.
This is my attempt: $m$ divides $a$ implies that $mn$ also divides $a$. How do I show that $n$ also divides $a$?