## Introductory Algebra for College Students (7th Edition)

$7+4i$
Using the properties of radicals and that $i=\sqrt{-1}$, then the given expression, $7+\sqrt{-16} ,$ is equivalent to \begin{array}{l}\require{cancel} 7+\sqrt{-1}\cdot\sqrt{16} \\\\= 7+i\cdot\sqrt{(4)^2} \\\\= 7+i\cdot4 \\\\= 7+4i .\end{array}