# Left-aligning equations

How do I left-align selective equation blocks, i.e. not centered ?

I know how to do it for ALL equation blocks in the document setting

\usepackage[fleqn]{amsmath}
\setlength{\mathindent}{0pt}


in the preamble, but I only want to do this for some equation blocks.

\documentclass[pdftex,12pt,a4paper,english,dutch,leqno]{article}
\usepackage{babel}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage[dvipsnames,table]{xcolor}
\usepackage{color}
\definecolor{vanillegeel}{RGB}{255,240,216}
\usepackage{empheq}

\begin{document}

De raaklijn aan $(x_{0},f(x_{0}))$ wordt algemeen bepaald met :
\begin{empheq}[box={\fboxsep=3pt\colorbox{vanillegeel}}]{align*}
\textnormal{$\begin{cases}z=f(x)\text{ is continu in }x_{0}\text{.}\\ f'(x_{0})=0\text{ : }z=f(x_{0})\text{ is de horizontale raaklijn.}\\ \lim_{x\to x_{0}} f'(x)=\pm\infty\text{ : }x=x_{0}\text{ is de verticale raaklijn.}\\ f'(x_{0})\in\mathbb{R}_{0}\text{ : }z-f(x_{0})=f'(x_{0})\cdot(x-x_{0})\text{ is de raaklijn.\hspace{-12pt}}\end{cases}$}\end{empheq}

\end{document}

• Place '&' at the beginning of each line inside the empheq environment and do not use the cases environment. This is the easiest way to get what you want. Jul 17, 2015 at 16:23

Don't use align*.

De raaklijn aan $(x_{0},f(x_{0}))$ wordt algemeen bepaald met:
\begin{flushleft}
\colorbox{vanillegeel}{%
$\displaystyle \begin{cases} z=f(x) \text{ is continu in } x_{0}. \\ f'(x_{0})=0 \text{ : } z=f(x_{0}) \text{ is de horizontale raaklijn.} \\ \lim_{x\to x_{0}} f'(x)=\pm\infty \text{ : } x=x_{0} \text{ is de verticale raaklijn.} \\ f'(x_{0})\in\mathbb{R}_{0} \text{ : } z-f(x_{0})=f'(x_{0})\cdot(x-x_{0}) \text{ is de raaklijn.} \end{cases}$\kern-\nulldelimiterspace\kern-2\arraycolsep}
\end{flushleft}


• What does \kern-\nulldelimiterspace\kern-2\arraycolsep} do in this ? Oct 5, 2012 at 14:28
• @Petoetje59 It's a substitute of your \hspace{-12pt} based on document parameters, rather than "calculation by eye". Oct 5, 2012 at 14:45
• Not allowing you to get the unsung hero badge! ;) +1.
– user11232
Oct 5, 2012 at 14:48
• @HarishKumar Darn! Oct 5, 2012 at 14:49
• How come \begin{align*} doesn't work but flushleft does? Sep 1, 2015 at 8:18