Answer
$\pm 9$
Work Step by Step
Solving the equation:
$\sqrt 81$
$=\sqrt (9)^2$
$=\pm 9$
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.