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

$x=-54$
Multiplying both sides by $-6$, then the solution to the given equation, $\dfrac{-x}{6}=9$, is \begin{array}{l}\require{cancel} -6\cdot\dfrac{-x}{6}=9\cdot(-6) \\\\ \dfrac{6x}{6}=-54 \\\\ x=-54 .\end{array}