# aligned-environment in tabularx - fail to align vertically

I try to have a simple tabularx-table in which the cell content is vertically aligned to the top. While this works as expected for text, two aligned-environments in adjacent cells are vertically centered for no reason I could find.

How do I get the content of the first tabularx-environment aligned to the top?

Thank you.

\documentclass[10pt,a4paper]{article}

\usepackage{lipsum}
\usepackage{amsmath}
\usepackage{tabularx}

\begin{document}

\begin{tabularx}{\textwidth}{X l}
\hline
\begin{aligned} a &= 1 \\ b &= 2 \end{aligned}
&
\begin{aligned} c =& 3 \end{aligned}\\
\hline
\end{tabularx}

\begin{tabularx}{\textwidth}{X l}
\hline
\lipsum[1]
&
\begin{aligned} c =& 3 \end{aligned}\\
\hline
\end{tabularx}

\end{document}


\begin{aligned}[t]