Answer
$\text{base: }
\dfrac{4}{y}
\\\text{exponent: }
7$
Work Step by Step
By definition, $x^a$ has a base of $x$ and an exponent of $a$. Hence, the given expression, $
\left(\dfrac{4}{y}\right)^7
$, has the following characteristics:
\begin{array}{l}\require{cancel}
\text{base: }
\dfrac{4}{y}
\\\text{exponent: }
7
.\end{array}