Math & Science ⇒ justify left only one subequation

[michaelart]

Hello

I would like to justify left only one subequation in an environment leaving the rest centered. Is there a way to do this?
Specifically my code is

Code: Select all

\begin{subequations}\label{eq:asymcoef}\begin{align}
\alpha_{j}=\left(\sum _{k=1}^{6}a_{kj}\right) \\
\text{and}\nonumber \\
\beta_{j}=\left(\sum _{k=1}^{6}b_{kj}\right)
\end{align}\end{subequations} 

I would like that "and" to appear to the left and still have the same number (1a) and (1b) in the two equations of alpha and beta

[localghost]

The amsmath user guide suggests the \intertext command for this case …

Code: Select all

\documentclass[11pt,a4paper]{article}
\usepackage{amsmath}

\begin{document}
  \begin{subequations}\label{eq:asymcoef}
    \begin{align}
      \alpha_{j}=\left(\sum _{k=1}^{6}a_{kj}\right) \\
      \intertext{and}
      \beta_{j}=\left(\sum _{k=1}^{6}b_{kj}\right)
    \end{align}
  \end{subequations}
\end{document}

… and the mathtools package enhances this with the \shortintertext command.

Code: Select all

\documentclass[11pt,a4paper]{article}
\usepackage{mathtools}   % loads »amsmath«

\begin{document}
  \begin{subequations}\label{eq:asymcoef}
    \begin{align}
      \alpha_{j}=\left(\sum _{k=1}^{6}a_{kj}\right) \\
      \shortintertext{and}
      \beta_{j}=\left(\sum _{k=1}^{6}b_{kj}\right)
    \end{align}
  \end{subequations}
\end{document}

Best regards and welcome to the board
Thorsten

[michaelart]

It works perfectly, thanks a lot Th