A vertically centered equation number on a multline environment
What you want is the multlined
environment provided by mathtools
:
\documentclass{article}
\usepackage{mathtools}
\begin{document}
\begin{equation}
\begin{multlined}
a+b+c+d+e+f+{}\\
g+h+i+j
\end{multlined}
\end{equation}
\end{document}
Try to use this:
\begin{equation}\label{xx}
\begin{split}
a&= b+c-d\\
& \quad +e-f\\
&= g+h\\
&= i
\end{split}
\end{equation}`
This answer is really just an addendum to/augmentation of the answer provided by @Thiago on the use of a split
environment within an equation
environment to get the vertical centering of the equation number.
Normally, one uses the
split
environment to align successive lines on a single common point -- frequently, not necessarily, an=
sign.However, by leaving off the align symbol,
&
, entirely from two (or more) consecutive lines, the resulting lines will simply be centered, one line after the other.Other alignment possibilities exist too. For example, the following code,
\begin{equation} \begin{split} a+b+c+{}&d=\\ &e+f+g+h \end{split} \end{equation}
serves to have the
e
of the second line be placed exactly below thed
of the first line.