Chapter R - Section R.3 - Exponents, Roots, and Order of Operations - R.3 Exercises - Page 30: 74

$-9$

Using order of operations and the properties of radicals, the given expression, $ \dfrac{(-9+\sqrt{16})(-3^2)}{-4-1} ,$ simplifies to \begin{array}{l}\require{cancel} \dfrac{(-9+4)(-9)}{-5} \\\\= \dfrac{(-5)(-9)}{-5} \\\\= \dfrac{(\cancel{-5})(-9)}{\cancel{-5}} \\\\= -9 .\end{array}