It is not clear what your question is so I offer two alternatives

\documentclass{article}
\usepackage{amsmath}
\begin{document}
Either
\[
7\frac{1}{6}=\frac{42+1}{6}=\frac{43}{6}
\]
or
\begin{center}
$ 7\frac{1}{6}=\frac{42+1}{6}=\frac{43}{6}$
\end{center}
\end{document}

I can't see any cases where you would want to set this as multiple math fragments in separate $...$ also avoid using \dfrac in most uses of inline math.

## Best Answer

It is not clear what your question is so I offer two alternatives

I can't see any cases where you would want to set this as multiple math fragments in separate

`$...$`

also avoid using`\dfrac`

in most uses of inline math.