#### Answer

$\left( \sqrt[]{r+2z} \right)^{3}$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
Use the definition of rational exponents to convert the given expression, $
(r+2z)^{3/2}
,$ to radical form.
$\bf{\text{Solution Details:}}$
Using the definition of rational exponents which is given by $a^{\frac{m}{n}}=\sqrt[n]{a^m}=\left(\sqrt[n]{a}\right)^m,$ the expression above is equivalent to
\begin{array}{l}\require{cancel}
\left( \sqrt[]{r+2z} \right)^{3}
.\end{array}