Math & Science ⇒ Fraction of fraction

[ladolcevita]

I would like to write fraction of fraction, that is attaced.
Could you help me with it ?

[Johannes_B]

Code: Select all

\documentclass{article}
\usepackage{mathtools}
\begin{document}
\[ F = \frac{(R^2_U - R^2_R)/q}{(1-R^2_U ) / (N-K)} \]
\end{document}