## College Algebra (6th Edition)

$\frac{(13\sqrt 11 - 39)}{2}$
$\frac{13}{(3 + \sqrt 11)}$ =$\frac{13\times(3 - \sqrt 11)}{(3 + \sqrt 11)\times(3 - \sqrt 11)}$ =$\frac{(39- 13\sqrt 11)}{3^{2} - \sqrt 11^{2}}$ =$\frac{(39- 13\sqrt 11)}{9 - 11}$ =$\frac{(39- 13\sqrt 11)}{- 2}$ =$\frac{(13\sqrt 11 - 39)}{2}$