## Elementary Algebra

$6y^{2}\sqrt {2xy}$
Breaking the radicand into its factors and simplifying, we obtain: $\sqrt {72xy^{5}}$ =$\sqrt {2\times36\times x \times y^{4}\times y}$ =$\sqrt {36\times y^{4}}\times\sqrt {2\times x\times y}$ =$\sqrt {6^{2}\times (y^{2})^{2}}\times\sqrt {2\times x\times y}$ =$6\times y^{2}\times\sqrt {2\times x\times y}$ =$6y^{2}\times\sqrt {2xy}$ =$6y^{2}\sqrt {2xy}$