Answer
If $a$ is a factor of $c$, then it means that $a$ divides $c$.
Work Step by Step
RECALL:
If a number $a$ is a factor of a number $b$, then $a$ divides $b$.
In symbols,
$a | b$.
Thus, if $a$ is a factor of $c$, then $a$ divides $c$.
In symbols, $a|c$.
