Center Formula in self created environment

Question

I use a environment called loesung which I created by myself. Now I have a formula in that environment, but I want to have that formulas centered. Not left aligned, here is my code:

%http://tex.stackexchange.com/questions/69043/center-formula-in-self-created-environment
\documentclass{book}

\usepackage[ngerman]{babel}
%\usepackage{geometry}
%\geometry{left=4cm,right=3cm, top=2cm, bottom=2cm} 
\usepackage{amsmath,amsthm}
\usepackage{mdframed}
\usepackage{xcolor}
\usepackage{hyperref}[2011/02/05]

\definecolor{cloesung}{rgb}{0.972,0.93725,0.85098}

\newtheoremstyle{mystyle2}
  {\topsep}{\topsep}{}{}%
  {\bfseries}{}{.5em}{}%

\newmdtheoremenv[hidealllines=true,
backgroundcolor=cloesung,skipabove=\topsep,
skipbelow=\topsep]{loesung}{L\"osung}

\begin{document}

\begin{loesung}\text{blafasel}\\
\begin{align*}
c &= a+b\\
\intertext{description} a+b \intertext{is ....}
d &= h+g
\end{align*}
\end{loesung}

\end{document}

So my problem is, that the formulas should be centered? How can I do this? I tried \centering and \begin{center} but it does not work?

Thanks a lot cya

Answer 1

Your problem has nothing to do with your self-created environment. Witness

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\hrule
\begin{align*}
  c &= a+b\\
  \intertext{description} a+b \intertext{is \dots}
  d &= h+g
\end{align*}
\hrule
\end{document}

So what you are really asking is how to do you center one equation in the middle of an alignment. That can be acheived by putting the extra equation inside the \intertext command in its own maths environment as follows:

\begin{align*}
  c &= a+b\\
  \intertext{description \begin{equation*} a+b \end{equation*} is \dots}
  d &= h+g
\end{align*}

Put into your sample environment this looks like:

However, I would generally avoid such widely separated alignments and write your example simply as

\begin{loesung}
  blafasel
  \begin{equation*}
c = a+b
\end{equation*}
description
\begin{equation*}
  a+b
\end{equation*}
is \dots
\begin{equation*}
d = h+g
\end{equation*}
\end{loesung}

Answer 2

I think that what you want is possibly this:

\begin{loesung}
\text{ }\\
\begin{align*}
c&=a+b\\
\intertext{description}
a+b\\ 
\intertext{is \dots}
d&=h+g
\end{align*}
\end{loesung}