为什么我不能垂直对齐这两个矩阵？

Question

为什么这些矩阵不会左对齐？

\documentclass[11pt,a4paper,oneside]{report} 
\usepackage[pdftex]{graphicx} 
\usepackage[T1]{fontenc} 
\usepackage{fouriernc}
\usepackage{mathtools}
\usepackage{amsfonts,amsmath,amssymb,amsthm}
\usepackage[a4paper, hmargin={3.5cm,3cm}, vmargin={2.5cm,2.5cm}]{geometry} % margin
\usepackage{multicol}


\begin{document}
\begin{align*}
&\renewcommand\arraystretch{1.4}
\begin{bmatrix}
a_{1}&u_{2}&\frac{a_{1}}{d}u_{3}\\
a_{2}&u_{1}&\frac{a_{2}}{d}u_{3}\\
a_{3}&0&u_{4}\\
\end{bmatrix}\\
\intertext{with} 
&\renewcommand\arraystretch{1.4}
\begin{vmatrix}
a_{1}&u_{2}&\frac{a_{1}}{d}u_{3}\\
a_{2}&u_{1}&\frac{a_{2}}{d}u_{3}\\
a_{3}&0&u_{4}
\end{vmatrix}=1
\end{align*}
\end{document}

谢谢

Answer 1

这是一个很肮脏的伎俩，但它确实有效。它对齐的是矩阵的元素，而不是分隔符。

\documentclass[11pt,a4paper,oneside]{report} 
\usepackage[pdftex]{graphicx} 
\usepackage[T1]{fontenc} 
\usepackage{fouriernc}
\usepackage{mathtools}
\usepackage{amsfonts,amsmath,amssymb,amsthm}
\usepackage[a4paper, hmargin={3.5cm,3cm}, vmargin={2.5cm,2.5cm}]{geometry} % margin
\usepackage{multicol}


\begin{document}
\begin{gather*}
\renewcommand\arraystretch{1.4}
\begin{bmatrix}
a_{1}&u_{2}&\frac{a_{1}}{d}u_{3}\\
a_{2}&u_{1}&\frac{a_{2}}{d}u_{3}\\
a_{3}&0&u_{4}\\
\end{bmatrix}\mathrel{\phantom{=1}}
\intertext{with} 
\renewcommand\arraystretch{1.4}
\begin{vmatrix}
a_{1}&u_{2}&\frac{a_{1}}{d}u_{3}\\
a_{2}&u_{1}&\frac{a_{2}}{d}u_{3}\\
a_{3}&0&u_{4}
\end{vmatrix}=1
\end{gather*}
\end{document}