Answer
$\dfrac{7}{2\sqrt[3]{49}}$
Work Step by Step
Rationalizing the numerator of $
\sqrt[3]{\dfrac{7}{8}}
$ results to
\begin{array}{l}
\sqrt[3]{\dfrac{7}{8}}
\cdot
\sqrt[3]{\dfrac{7^2}{7^2}}
\\\\=
\sqrt[3]{\dfrac{7^3}{8\cdot7^2}}
\\\\=
\dfrac{7}{2\sqrt[3]{49}}
.\end{array}