Answer
$n=\left\{ -\dfrac{8}{7},4 \right\}$
Work Step by Step
Using the Distributive Property, the given expression, $
3n(7n-20)=96
,$ simplifies to
\begin{array}{l}\require{cancel}
3n(7n)+3n(-20)=96
\\\\
21n^2-60n=96
\\\\
21n^2-60n-96=0
\\\\
\dfrac{21n^2-60n-96}{3}=\dfrac{0}{3}
\\\\
7n^2-20n-32=0
\\\\
(7n+8)(n-4)=0
\\\\
n=\left\{ -\dfrac{8}{7},4 \right\}
.\end{array}
