Several lines of formulas to the left of one curly brace pointing to equation number

How to make several lines of equations under one curly brace from the left side, such that it point to a reference number.

Now I do something like this:

\begin{align}
\left.
\begin{array}{ll}
a = b + c \\
& \dots  \\
a = b + c \\
& \dots  \\
a = b + c
\end{array}
\right\} \label{formulas}\\
\end{align}

But equation number appears in the bottom of curly brace.

Looks like you have an extra line break \\ to the right of your label. If you delete it, the output should look fine. \documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{align}
\left.
\begin{array}{ll}
a = b + c \\
& \dots  \\
a = b + c \\
& \dots  \\
a = b + c
\end{array}
\right\} \label{formulas}
\end{align}

\end{document}
• Side note: no point in using an align environment here; an equation would do. – jub0bs Apr 6 '13 at 23:10
• Thank, it was stupid mistake. Did not notice. – ashim Apr 6 '13 at 23:12
• @Jubobs: You're right! Thanks for pointing out. I was trying to stick to OP's codes as close as possible, and didn't even think too much about the environment being used. – Herr K. Apr 6 '13 at 23:15

I would use rcases from the mathtools package for this- it loads and extends the amsmath package. Code

% arara: pdflatex
\documentclass{article}

\usepackage{mathtools}

\begin{document}

\begin{equation}
\begin{rcases}
a = b + c \\
& \dots \\
a = b + c \\
& \dots \\
a = b + c
\end{rcases}
\label{formulas}
\end{equation}

\end{document}