# vertical alignment of multiline equations

I tried in many ways to vertically align these equations but I failed to get it right.

\documentclass[11pt,a4paper,oneside]{report}
\usepackage[T1]{fontenc}
\usepackage{fouriernc}
\usepackage{mathtools}
\usepackage{amsthm}

\begin{document}
first attempt
\begin{aligned} &-\omega\cdot \alpha_{1}=\bigl|B_{1}A_{2}A_{3}\bigr|\cdot \alpha_{1}+\bigl|A_{1}B_{1}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{1}\bigr|\cdot \alpha_{3} \\ &-\omega\cdot \alpha_{2}=\bigl|B_{2}A_{2}A_{3}\bigr|\cdot \alpha_{1}+\bigl|A_{1}B_{2}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{2}\bigr|\cdot \alpha_{3} \\ &-\omega\cdot \alpha_{3}=\bigl|B_{3}A_{2}A_{3}\bigr|\cdot \alpha_{1}+\bigl|A_{1}B_{2}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{2}\bigr|\cdot \alpha_{3} \\ &-\theta\cdot \alpha_{1}=\bigl|A_{1}B_{2}B_{3}\bigr|\cdot \alpha_{1}+\bigl|B_{1}A_{1}B_{3}\bigr|\cdot \alpha_{2}+\bigl|B_{1}B_{2}A_{1}\bigr|\cdot \alpha_{3} \\ &-\theta\cdot \alpha_{1}=\bigl|A_{1}B_{2}B_{3}\bigr|\cdot \alpha_{1}+\bigl|B_{1}A_{1}B_{3}\bigr|\cdot \alpha_{2}+\bigl|B_{1}B_{2}A_{1}\bigr|\cdot \alpha_{3} \end{aligned}

second attempt
\begin{alignat*}{3}
&-\omega\cdot \alpha_{1}=&&\bigl|B_{1}A_{2}A_{3}\bigr|\cdot \alpha_{1}+&&\bigl|A_{1}B_{1}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{1}\bigr|\cdot \alpha_{3}  \\
&-\omega\cdot \alpha_{2}=&&\bigl|B_{2}A_{2}A_{3}\bigr|\cdot \alpha_{1}+&&\bigl|A_{1}B_{2}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{2}\bigr|\cdot \alpha_{3} \\
& -\theta\cdot \alpha_{3}=&&\bigl|B_{3}A_{2}A_{3}\bigr|\cdot \alpha_{1}+&&\bigl|A_{1}B_{2}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{2}\bigr|\cdot \alpha_{3}  \\
&-\theta\cdot \alpha_{1}=&&\bigl|A_{1}B_{2}B_{3}\bigr|\cdot \alpha_{1}+&&\bigl|B_{1}A_{1}B_{3}\bigr|\cdot \alpha_{2}+\bigl|B_{1}B_{2}A_{1}\bigr|\cdot \alpha_{3}
\end{alignat*}

third attempt
$$\begin{split} &-\omega\cdot \alpha_{1}=\bigl|B_{1}A_{2}A_{3}\bigr|\cdot \alpha_{1}+\bigl|A_{1}B_{1}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{1}\bigr|\cdot \alpha_{3} \\ &-\omega\cdot \alpha_{2}=\bigl|B_{2}A_{2}A_{3}\bigr|\cdot \alpha_{1}+\bigl|A_{1}B_{2}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{2}\bigr|\cdot \alpha_{3} \\ &-\omega\cdot \alpha_{3}=\bigl|B_{3}A_{2}A_{3}\bigr|\cdot \alpha_{1}+\bigl|A_{1}B_{2}A_{3}\bigr|\cdot \alpha_{2}+\bigl|A_{1}A_{2}B_{2}\bigr|\cdot \alpha_{3} \\ &-\theta\cdot \alpha_{1}=\bigl|A_{1}B_{2}B_{3}\bigr|\cdot \alpha_{1}+\bigl|B_{1}A_{1}B_{3}\bigr|\cdot \alpha_{2}+\bigl|B_{1}B_{2}A_{1}\bigr|\cdot \alpha_{3} \\ &-\theta\cdot \alpha_{1}=\bigl|A_{1}B_{2}B_{3}\bigr|\cdot \alpha_{1}+\bigl|B_{1}A_{1}B_{3}\bigr|\cdot \alpha_{2}+\bigl|B_{1}B_{2}A_{1}\bigr|\cdot \alpha_{3} \end{split}$$

\end{document}


produces

The first attempt aligns only first three rows, but not the last two (they are aligned with one another but not with the rest), while the second attempt almost fixes everything except the third and the fourth column but I don't get a numbering in the middle. The last one seems to be like the first one. Could someone help me with this? Thank you.

• ω is wider than θ and A is wider than B. So it is impossible to align everything... – Symbol 1 Sep 12 '14 at 11:00

You have to decide first, if you want to have one equation and hence only one number or multiple equations with multiple numbers (for this choice see the remark at the end of the post). For the first use and with an ed environment (like aligned, gathered). Since you have multiple alignment points, you should use the alignedat environment.

Here the MWE (including the preamble):

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{alignedat}{8} &-\omega &&\cdot \alpha_{1} &&= \bigl|B_{1}A_{2}A_{3}\bigr| &&\cdot \alpha_{1} &&+ \bigl|A_{1}B_{1}A_{3}\bigr| &&\cdot \alpha_{2} &&+ \bigl|A_{1}A_{2}B_{1}\bigr| &&\cdot \alpha_{3} \\ &-\omega &&\cdot \alpha_{2} &&= \bigl|B_{2}A_{2}A_{3}\bigr| &&\cdot \alpha_{1} &&+ \bigl|A_{1}B_{2}A_{3}\bigr| &&\cdot \alpha_{2} &&+ \bigl|A_{1}A_{2}B_{2}\bigr| &&\cdot \alpha_{3} \\ &-\theta &&\cdot \alpha_{3} &&= \bigl|B_{3}A_{2}A_{3}\bigr| &&\cdot \alpha_{1} &&+ \bigl|A_{1}B_{2}A_{3}\bigr| &&\cdot \alpha_{2} &&+ \bigl|A_{1}A_{2}B_{2}\bigr| &&\cdot \alpha_{3} \\ &-\theta &&\cdot \alpha_{1} &&= \bigl|A_{1}B_{2}B_{3}\bigr| &&\cdot \alpha_{1} &&+ \bigl|B_{1}A_{1}B_{3}\bigr| &&\cdot \alpha_{2} &&+ \bigl|B_{1}B_{2}A_{1}\bigr| &&\cdot \alpha_{3} \end{alignedat}

\end{document}


Remark: For multiple equations: Replace with \begin{alignat}{8}, with \end{alignat}, and delete \begin{alignedat}{8} and \end{alignedat}.