我有类似的东西：
\begin{align}
a &= b+c & d &=e+f & g &=h+i\\
a &= b+c & d &=e+f & g &=h+i\\
%%%%%
a+h+q &= b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q+r+s+t\\
&\quad +u+x+y+w+z
%%%%%
\\
a &= b+c & d &=e+f & g &=h+i \\
\end{align}
我试图将第三个方程在第一个“列”上彼此对齐，并像在环境中&一样将其连续跨越。\multicolumntabular
一些尝试
一
我已经尝试tabular过multicolumn：
\begin{align}
\setlength{\tabcolsep}{0pt}
\begin{tabular}{>{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$}}
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i\\
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i\\
\multicolumn{6}{>{$}l<{$}}{\,\,a+h+q = b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q}\\
& \multicolumn{5}{>{$}l<{$}}{\quad +r+s+t+u+x+y+w+z}\\
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i
\end{tabular} \notag\\
\end{align}
\begin{equation*}
\setlength{\tabcolsep}{0pt}
\begin{tabular}{>{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}r<{$}}
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i &\quad (2)\\
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i & \quad (3)\\
\multicolumn{6}{>{$}l<{$}}{\,\,a+h+q = b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q}& \\
& \multicolumn{5}{>{$}l<{$}}{\quad +r+s+t+u+x+y+w+z} & \quad (4) \\
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i & \quad (5)
\end{tabular}
\end{equation*}
二
我已经尝试过 TikZ 和 tikzlibraryfit并且matrix：
\begin{equation*}
\begin{tikzpicture}
\matrix (table) [matrix of math nodes, nodes in empty cells, row sep=.25em, column sep=0em]{%
\phantom{a+h+q}a &=& b+c &\qquad d &=& e+f &\qquad g &=& h+1 &\node[xshift=8.5em]{(6)};\\
\phantom{a+h+q}a &=& b+c &\qquad d &=& e+f &\qquad g &=& h+1 & \node[xshift=8.5em]{(7)};\\
\,\, a+h+q & & &\qquad & & &\qquad & & & \\
& & &\qquad & & &\qquad & & & \node[xshift=8.5em]{(8)};\\
\phantom{a+h+q}a &=& b+c &\qquad d &=& e+f &\qquad g &=& h+1 & \node[xshift=8.5em]{(9)};\\
};
\node[yshift=0.95em,fit=(table-3-2)(table-3-3)(table-3-4)(table-3-5)(table-3-6)(table-3-7)(table-3-8)(table-3-9)]{$$=\,\,b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q$$};
\node[yshift=0.95em,xshift=-.9em,fit=(table-4-2)(table-4-3)(table-4-4)(table-4-5)(table-4-6)(table-4-7)(table-4-8)(table-4-9)]{$$+r+s+t+u+x+y+w+z$$};
\end{tikzpicture}
\end{equation*}
是否可以在数学模式下执行此操作，即是否有合适的环境来执行此操作？
平均能量损失
\documentclass{article}
\usepackage{amsmath}
\usepackage{array}
\usepackage{tikz}
\usetikzlibrary{fit,matrix}
\begin{document}
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus elit, vestibulum ut, placerat ac, adipiscing vitae, felis.
\begin{align}
\setlength{\tabcolsep}{0pt}
\begin{tabular}{>{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$}}
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i\\
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i\\
\multicolumn{6}{>{$}l<{$}}{\,\,a+h+q = b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q}\\
& \multicolumn{5}{>{$}l<{$}}{\quad +r+s+t+u+x+y+w+z}\\
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i
\end{tabular} \notag\\
\end{align}
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus elit, vestibulum ut, placerat ac, adipiscing vitae, felis.
\begin{equation*}
\setlength{\tabcolsep}{0pt}
\begin{tabular}{>{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}l<{$} >{$}r<{$}}
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i &\quad (2)\\
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i & \quad (3)\\
\multicolumn{6}{>{$}l<{$}}{\,\,a+h+q = b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q}& \\
& \multicolumn{5}{>{$}l<{$}}{\quad +r+s+t+u+x+y+w+z} & \quad (4)\\
\phantom{a+h+q}a &\,= b+c &\qquad d &\,=e+f &\qquad g &\,=h+i & \quad (5)
\end{tabular}
\end{equation*}
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus elit, vestibulum ut, placerat ac, adipiscing vitae, felis.
\begin{equation*}
\begin{tikzpicture}
\matrix (table) [matrix of math nodes, nodes in empty cells, row sep=.25em, column sep=0em]{%
\phantom{a+h+q}a &=& b+c &\qquad d &=& e+f &\qquad g &=& h+1 &\node[xshift=8.5em]{(6)};\\
\phantom{a+h+q}a &=& b+c &\qquad d &=& e+f &\qquad g &=& h+1 & \node[xshift=8.5em]{(7)};\\
\,\, a+h+q & & &\qquad & & &\qquad & & & \\
& & &\qquad & & &\qquad & & & \node[xshift=8.5em]{(8)};\\
\phantom{a+h+q}a &=& b+c &\qquad d &=& e+f &\qquad g &=& h+1 & \node[xshift=8.5em]{(9)};\\
};
\node[yshift=0.95em,fit=(table-3-2)(table-3-3)(table-3-4)(table-3-5)(table-3-6)(table-3-7)(table-3-8)(table-3-9)]{$$=\,\,b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q$$};
\node[yshift=0.95em,xshift=-.9em,fit=(table-4-2)(table-4-3)(table-4-4)(table-4-5)(table-4-6)(table-4-7)(table-4-8)(table-4-9)]{$$+r+s+t+u+x+y+w+z$$};
\end{tikzpicture}
\end{equation*}
\end{document}
答案1
有两个问题：首先，在对齐其他方程式时忽略长方程式。其次，将长方程式置于显示区域的中心。第一个问题通过\mathrlap(来自 mathtools} 实现，第二个问题通过使用flalign和实现\hspace。
\documentclass{article}
\usepackage{showframe}
\usepackage{mathtools}
\newlength{\tempdima}
\begin{document}
\settowidth{\tempdima}{$\displaystyle a+h+q = b+c+d+e+f+g+h+i+j+k+l+m+n+o+p$}%
\setlength{\tempdima}{\dimexpr 0.5\textwidth - 0.5\tempdima}%
\begin{flalign}
a &= b+c & d &=e+f & g &=h+i &\\
a &= b+c & d &=e+f & g &=h+i \\
\hspace{\tempdima}
a+h+q &= \mathrlap{b+c+d+e+f+g+h+i+j+k+l+m+n+o+p}\notag\\[-1ex]
&\quad \mathrlap{{}+u+x+y+w+z}\\
a &= b+c & d &=e+f & g &=h+i
\end{flalign}
\end{document}
