Chapter R - Elementary Algebra Review - R.2 Equations, Inequalities, and Problem Solving - R.2 Exercise Set - Page 946: 9

$x=42$

Using the properties of equality, the value of the variable that satisfies the given expression, $ -\dfrac{2}{7}x=-12 ,$ is \begin{array}{l}\require{cancel} -\dfrac{7}{2}\left(-\dfrac{2}{7}x\right)=-12\left(-\dfrac{7}{2} \right) \\\\ x=\dfrac{84}{2} \\\\ x=42 .\end{array}