Chapter 10 - Exponents and Radicals - 10.2 Rational Numbers as Exponents - 10.2 Exercise Set - Page 641: 71

$3^{\frac{3}{4}}$

Using the laws of exponents, the given expression, $ \dfrac{3^{5/8}}{3^{-1/8}} ,$ simplifies to \begin{array}{l}\require{cancel} 3^{\frac{5}{8}-\left( -\frac{1}{8} \right)} \\\\= 3^{\frac{5}{8}+\frac{1}{8}} \\\\= 3^{\frac{6}{8}} \\\\= 3^{\frac{3}{4}} .\end{array}