Answer
$\dfrac{1}{n^4}$
Work Step by Step
Using the laws of exponents, the given expression, $
\dfrac{n^{-1}}{n^{3}}
,$ is equivalent to
\begin{array}{l}\require{cancel}
n^{-1-3}
\\\\=
n^{-4}
\\\\=
\dfrac{1}{n^4}
.\end{array}
For more complicated problems, it is helpful to remember that you can flip the location of numbers with negative exponents. In other words, you can move numbers with a negative exponent that are in the numerator to the denominator, and you can move numbers with a negative exponent in the denominator to the numerator.
