Chapter 9 - Section 9.5 - Logarithmic Functions - Exercise Set - Page 572: 88

$x-5$

Factoring the given expressions and cancelling the common factors between the numerator and the denominator, the given rational expression, $ \dfrac{x^2-3x-10}{2+x} ,$ simplifies to \begin{array}{l}\require{cancel} \dfrac{(x-5)(x+2)}{x+2} \\\\= \dfrac{(x-5)(\cancel{x+2})}{\cancel{x+2}} \\\\= x-5 .\end{array}