Chapter 6 - Section 6.2 - Adding and Subtracting Rational Expressions - Exercise Set - Page 355: 96

The error is that the $LCD$ should be $x+7$ and not $(x+7)^2$; $\dfrac{-x+4}{x+7}$

The error is that the $LCD$ should be $x+7$ and not $(x+7)^2$. The correct solution is \begin{array}{l}\require{cancel} \dfrac{7-(x+3)}{x+7} \\\\= \dfrac{7-x-3}{x+7} \\\\= \dfrac{-x+4}{x+7} .\end{array}