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

$\sqrt{77xy}$
Using $\sqrt{x}\cdot\sqrt{y}=\sqrt{xy}$ or the product rule of radicals, the given expression, $\sqrt{7x}\cdot\sqrt{11y} ,$ is equivalent to \begin{array}{l}\require{cancel} \sqrt{7x(11y)} \\\\= \sqrt{77xy} .\end{array}