Hi guys.

The teacher in our class made some claim and didn't prove it for some reason, and I really want to see the proof for that.

let $\displaystyle n,m,d\in \mathbb{Z}$.

if $\displaystyle d|n$ and $\displaystyle d|m$ then $\displaystyle d|(am+bn)$ for every $\displaystyle a,b\in\mathbb{Z}$.

thanks in advanced.