# Aligning two multiline equations [duplicate]

I searched a lot for this but couldn't find an answer. Say I have two equations that are 2 lines long each. I can align each equation at their equality sign using equation-aligned or gather-split, like this:

\begin{gather}
\begin{split}
a &=b \\
&=c
\end{split}
\\
\begin{split}
k &=l+55 \\
&=d+401
\end{split}
\end{gather}

However, I can't find a way to align the equality signs of both sets of code. Any solutions?

## marked as duplicate by Sigur, Gonzalo Medina, Community♦Jul 14 '15 at 15:20

Just change gather into align:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{align}
\begin{split}
a &=b \\
&=c
\end{split}
\\
\begin{split}
k &=l+55 \\
&=d+401
\end{split}
\end{align}

\end{document}

If you pass the tbtags option to amsmath, you get the equation numbers aligned with the bottom line instead of centered on the split.

\documentclass{article}
\usepackage[tbtags]{amsmath}

\begin{document}

\begin{align}
\begin{split}
a &=b \\
&=c
\end{split}
\\
\begin{split}
k &=l+55 \\
&=d+401
\end{split}
\end{align}

\end{document}