Answer
$\dfrac{5b}{7}$
Work Step by Step
Cancelling the common factor between the numerator and the denominator, the given expression, $
\dfrac{65abc}{91ac}
,$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{\cancel{13ac}\cdot5b}{\cancel{13ac}\cdot7}
\\\\=
\dfrac{5b}{7}
\end{array}
