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

$m=\dfrac{E}{c^2}$
$\bf{\text{Solution Outline:}}$ To solve the given equation, $E=mc^2$ for $m ,$ use the properties of equality to isolate the variable. $\bf{\text{Solution Details:}}$ Using the properties of equality to isolate the variable, the equation above is equivalent to \begin{array}{l}\require{cancel} E=mc^2 \\\\ \dfrac{E}{c^2}=\dfrac{mc^2}{c^2} \\\\ \dfrac{E}{c^2}=m \\\\ m=\dfrac{E}{c^2} .\end{array}