Answer
{$\pm11$}
Work Step by Step
According to the square root property,
if $x^{2}=121$
then $x=\sqrt (121)=11$ or $x=-\sqrt (121)=-11$
Therefore, the solution set is {$-11,+11$} or {$\pm11$}
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.