## Elementary Algebra

$3$
Using $a^{-x}=\dfrac{1}{a^x}$ or $\dfrac{1}{a^{-x}}=a^x$ and the laws of exponents, the given expression, $\dfrac{1}{3^{-1}} ,$ is equivalent to \begin{array}{l}\require{cancel} 3^1 \\\\= 3 .\end{array}