Answer
$z=6$ or $z=-3$
Work Step by Step
$z^2-3z-18=0$
$(z-6)(z+3)=0$
$z-6=0$ or $z+3=0$
$z=6$ or $z=-3$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.