## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$t=\pm12$
Since $x^2=a$ implies $x=\pm\sqrt{a}$ (the Square Root Principle), the solutions to the given equation, $t^2=144 ,$ are \begin{array}{l}\require{cancel} t=\pm\sqrt{144} \\\\ t=\pm\sqrt{(12)^2} \\\\ t=\pm12 .\end{array}