Introductory Algebra for College Students (7th Edition)

$x=\{ -16,6 \}$
Taking the square root of both sides (the Square Root Property), the solutions to the given equation, $(x+5)^2=121 ,$ are \begin{array}{l}\require{cancel} (x+5)=\pm\sqrt{121} \\\\ x+5=\pm\sqrt{(11)^2} \\\\ x+5=\pm11 \\\\ x=-5\pm11 .\end{array} Hence, $x=\{ -16,6 \} .$