Answer
$\text{radicand: }
\dfrac{x}{y+4}
\\\text{index: }
5
$
Work Step by Step
The radicand and the index of the given expression, $
x^2y^3\sqrt[5]{\dfrac{x}{y+4}}
,$ are
\begin{array}{l}
\text{radicand: }
\dfrac{x}{y+4}
\\\text{index: }
5
.\end{array}
In the expression $\sqrt[y] x$, y is the index while x is the radicand.