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

$\sqrt{2} + \sqrt{11}$ (cannot be simplified further)
A radical involving a square is already in lowest terms when the radicand has no perfect square factor. Note that the radicands of $\sqrt{2}$ amd $\sqrt{11}$ are prime numbers, which means that they have no factors other than themselves. Therefore, the given expression is already in lowest terms.