答案1
这是一个解决方案blkarray
:
\documentclass{article}
\usepackage{amsmath}
\usepackage{blkarray,bigstrut}%
\begin{document}
\[ \makeatletter\global\setlength\BA@colsep{3pt}\setlength{\arraycolsep}{3pt}\makeatother
\begin{blockarray}{(c<{\hspace{-0.95em}})}
\begin{blockarray}{*{5}{c}}
\begin{block}{*{5}{c} <{\hspace{1em}}\Right{\}}{$ x $}}
0 & ... & 0 & ... & 0 \bigstrut[t]\\
⋮ & ⋱ & ⋮ & ⋱ & ⋮ \\
0 & ... & 0 & ... & 0\\
\end{block}
\begin{block}{*{3}{c}\BAmultirow{4mm}\BAmultirow{2mm}}
⋮ & ⋱ & ⋮ & \BAmulticolumn{2}{l}{\: \mbox{\Large$ A $}} \\
\BAmulticolumn{3}{c}{\smash{\underbrace{\begin{matrix}0 & \mkern 1mu ... & \: 0\end{matrix}}_{\textstyle y}}}\\[-2ex]
\end{block}
\end{blockarray}
\end{blockarray} \]
\end{document}