## Intermediate Algebra (12th Edition)

$\dfrac{2}{7n}-\dfrac{3}{2m}+\dfrac{9}{7mn}$
Dividing the denominator to each of the terms of the numerator, the given expression, $\dfrac{4m^2n^2-21mn^3+18mn^2}{14m^2n^3} ,$ simplifies to \begin{array}{l}\require{cancel} \dfrac{4m^2n^2}{14m^2n^3}-\dfrac{21mn^3}{14m^2n^3}+\dfrac{18mn^2}{14m^2n^3} \\\\= \dfrac{2}{7n}-\dfrac{3}{2m}+\dfrac{9}{7mn} .\end{array}