## Intermediate Algebra (6th Edition)

$\dfrac{1}{x-7}$
Factoring the expressions and then cancelling the common factor/s between the numerator and the denominator, the given expression, $\dfrac{x+7}{x^2-49} ,$ simplifies to \begin{array}{l}\require{cancel} \dfrac{x+7}{(x+7)(x-7)} \\\\= \dfrac{\cancel{x+7}}{(\cancel{x+7})(x-7)} \\\\= \dfrac{1}{x-7} .\end{array}