# Left-alignment like Fleqn-option only for specific equations

I want to left-align some equations. (Note: I want to align the equations themselves, not code inside of the equations.)

I have the following example code:

\documentclass{scrartcl}
\usepackage{amsmath}
\begin{document}

\text{I want to left-align this equation}

$$\text{and this one,}$$

$$\text{but not this one and others.}$$

\end{document}


How can I achieve this? The equations don't neccessarily have to be left-adjusted to the left text border, the more important goal is to align them to each other.

You can use the flalign and flalign* environments from amsmath.

\documentclass{minimal}
\usepackage{amsmath}
\begin{document}
\noindent The quick brown fox jumps over the lazy dog.
\begin{equation*}
A = B
\end{equation*}
\begin{flalign*}
C = D &&
\end{flalign*}
\begin{flalign*}
E = F &&
\end{flalign*}
\end{document}


Does not work with \split in equation environment

• Thanks a lot, I already had tried flalign, but as I didn't know about the & at the end, it didn't work then... – meep.meep Apr 28 '11 at 11:30
• Why is an extra & needed at the end? – HackerBoss Apr 9 at 18:51
• @HackerBoss --- Short answer: try deleting them and see what happens. Long answer: flalign is usually used for multiple columns of equations. It works by stretching the space between columns (see the amsmath package documentation). The first ampersand is usually an alignment point within the equations (but the OP didn't want this; hence it's at the end of the line). The second ampersand denotes the end of the column and generates the stretching space, aligning the first column of equations against the left margin. – Ian Thompson Apr 12 at 7:56

I wanted to show an eplain version:

\input eplain
\leftdisplays
\hbox{I want to left-align this equation} \eqno(1.1)
$$\hbox{and this one,}$$
\centereddisplays
$$\hbox{but not this one and others} \eqno(1.2)$$
\bye


because of the following remark from the documentation:

It is usually poor typography to have both centered and left-justified displays in a single publication, though.

• I agree with you on that issue. I just want to use this in my appendix. But Thanks for this notice anyway :) – meep.meep Apr 28 '11 at 16:18