Prove or disprove the following:
For all integers a, b, and c, if ab | c then a | c and b | c
I'm having trouble proving the above. It seems to be obviously true in my head (but only because of all the examples I can think of), but I'm having trouble proving it.
Hint. By definition, $x\mid y$ if and only if there exists an integer $z$ so that $y=xz$. So if $ab\mid c$, write $c=(ab)(d)$ for some integer $d$. What does this tell you when you observe that $(ab)(d)=a(bd)=b(ad)$?