I want to align equations inside an enumeration, so I use the aligned environment and its [t] option to make the first equation appear on the same baseline as the item label:
\documentclass{article}
\usepackage{amsmath, enumitem}
\begin{document}
\begin{enumerate}[align=left, leftmargin=*, label=\large\sffamily\bfseries \alph*)]
\item $a = 1$
\item
$
\begin{aligned}[t]
a &= 1\\
b &= 2\\
c &= 3
\end{aligned}
$
\end{enumerate}
\end{document}
This works quite well, but I noticed that the aligned environment introduces a small indentation (I added the red line for better visualization):
How can this be solved? Or is there an even better alternative to aligned?
\!before\begin{aligned}; the problem has already been discussed here: Why is there a space at the beginning of the aligned environment – egreg Nov 14 '13 at 14:45