# how to set the left margin for all formulas in the text?

My text includes description of a formula and its equation right after that. But each time that I add a new item (description) the corresponding formulas have different indent. How can I change it such that when looking at the whole page, I see all the formulas having the same indent. Here is the code:

\item a
\begin{align}
&\sum_{k=1}^{K} ... \label{bal2}&\\
&\sum_{k=4}^{5}...  \label{bal3}&\
\label{bal3}\end{align}
\item b
\begin{align}
&\sum_{j=1}^{J}... \label{bal4}&\
\end{align}

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I am not sure I understand exactly how you want them aligned. Your given example shows them aligned on the left. The align environment centers the equations. If you want them aligned on the left when the width of the equations changes then use flalign. –  Peter Grill Mar 21 '12 at 23:09
While code snippets are useful in explanations, it is always best to compose a fully compilable MWE that illustrates the problem including the \documentclass and the appropriate packages so that those trying to help don't have to recreate it. –  Peter Grill Mar 21 '12 at 23:10
the default is to have equations centered. use can use \documentclass[fleqn]{article} to have all equations start a given distance from the left margin. this distance can be modified using e.g. \setlength{\mathindent}{2cm} –  prettygully Mar 21 '12 at 23:51
To build on the comments of @PeterGrill and @prettygully, you may also want to change the equation environment from align to gather since you're not instructing amsmath to align vertically the equations on any internal point (say, an equal sign). Making this change will let you get rid of the distracting & alignment points. –  Mico Mar 22 '12 at 0:17

From the comment of prettygully: The default is to have equations centered. use can use \documentclass[fleqn]{article} to have all equations start a given distance from the left margin. this distance can be modified using e.g. \setlength{\mathindent}{2cm}