Answer
I cannot vote if and only if I'm not registered or I'm not a citizen.
Work Step by Step
The English equivalent the given statement is:
$\sim r$: I cannot vote
$\sim p$: I'm not registered
$\sim q$: I'm not a citizen
Thus,
$\sim r \leftrightarrow (\sim p \vee \sim q):
I cannot vote if and only if I'm not registered or I'm not a citizen.
