# Aligning equations in two columns, but having one equation centered

Say I have 5 equations, and I want to align them such that the first equation is centered, and the other four equations are aligned in two columns. If I use the align environment, (I am using the amsart document class), and do the following

\begin{align}
a=A
\end{align}
\begin{align}
b&=B & c&=C \\
d&=D & e&=E
\end{align}


then the resulting gap after the first equation will be bigger than that between the rest of the equations. How can I do that better?

Thanks for suggestions!

If it is ok to have a shared number for the two column part you can use

\documentclass[a4paper]{article}
\usepackage{amsmath,amssymb}
\begin{document}
\begin{gather}
a=A
\\
\begin{aligned}
b&=B & c&=C
\\
d&=D & e&=E
\end{aligned}
\end{gather}
\end{document}


Note also this is the preferred method for giving example code, a self contained full but minimal example, others can copy and test as is.

Edit: as Barbara notes in the comments align is actually allowed inside a gather (normally these display math envs cannot be nested, which is why I used the inner variant aligned above). Here is the same MWE with gather + align:

\documentclass[a4paper]{article}
\usepackage{amsmath,amssymb}
\begin{document}
\begin{gather}
a=A
\\
\begin{align}
b&=B & c&=C
\\
d&=D & e&=E
\end{align}
\end{gather}
\end{document}


• Actually, align can be used inside gather. See the "Explanation" at the bottom of page 26 in the amsmath user's guide. – barbara beeton Sep 4 '19 at 17:23
• @barbarabeeton interesting, never realised that. – daleif Sep 5 '19 at 13:50

Here is a proposition with alignat and 3 columns:

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{alignat}{3}
& & & a =A \\
b&=B &\hspace{3.5em}& & \hspace{3.5em}c&=C \\
d&=D & & & e&=E
\end{alignat}

\end{document}