# Math Help - provind mods in series, sequences, integers and functions

1. ## provind mods in series, sequences, integers and functions

Show that if a, b, c, and d are integers such that
a | c and b | d, then ab | cd.

2. Originally Posted by racewithferrari
Show that if a, b, c, and d are integers such that
a | c and b | d, then ab | cd.
From $a|c$ we get that for some $m \in \mathbb{N}$, c = am. Also, from $b|d$ we get that for some $n \in \mathbb{N}$, d = nb.

Now, what is ab? Can you see how the above facts help us show the desired result?