Chapter 10 - Exponents and Radicals - 10.3 Multiplying Radical Expressions - 10.3 Exercise Set - Page 647: 59

$3\sqrt{22}$

Using the properties of radicals, the given expression, $ \sqrt{6}\sqrt{33} ,$ simplifies to \begin{array}{l}\require{cancel} \sqrt{6(33)} \\\\= \sqrt{3\cdot2(3\cdot11)} \\\\= \sqrt{(3)^2\cdot2\cdot11} \\\\= \sqrt{(3)^2\cdot22} \\\\= 3\sqrt{22} \end{array}