I'm using the following code. What should I do if I don't want the fixed indent from the left margin of my page?
\documentclass[fleqn,oneside]{article}
\usepackage{amsmath}
....
\begin{align}
a_1& =b_1+c_1\\
a_2& =b_2+c_2-d_2+e_2
\end{align}
[Tex/LaTex] problem using option fleqn in amsmath package
alignamsmathindentation
Related Solutions
Your alignment is perhaps better obtained using a structure like array:
\documentclass{article}
\usepackage{amsmath}% http://ctan.org/pkg/amsmath
\begin{document}
\begin{align*}
&a_1,\ &b_1,\ &c_1,\ &d_1,\ &e_1\ \text{etc.}\\
&a_2,\ &b_2,\ &c_2,\ &d_2,\ &e_2\ \text{etc.}
\end{align*}
\[
\begin{array}{*{6}{l@{\ }}}
a_1, & b_1, & c_1, & d_1, & e_1 & \text{etc.} \\[\jot]
a_2, & b_2, & c_2, & d_2, & e_2 & \text{etc.}
\end{array}
\]
\end{document}
The array consists of 6 l@{\ } columns - left-aligned, followed by a control-space \. \\[\jot] ensures a sizeable gap between the series, similar to that of align, while \text (provided by amsmath) does some testing to maintain the font size and is therefore superior to an \mbox construct (in general). In this case, it doesn't matter though.
Don't use align. Use gather instead.
\documentclass[fleqn]{article}
\usepackage{amsmath}
\begin{document}
\begin{gather}
b := (a \oplus s_1) \oplus s_2 \\
e := 0
\end{gather}
\end{document}
Best Answer
Set the length
\mathindentto zero: