\documentclass[12pt]{article}
\usepackage{amssymb,amsmath,amscd,concmath,amsfonts}
\usepackage{color}
\pagestyle{empty}
\begin{document}
\begin{equation*}
  \aligned 
    (M+m) \ddot p - ml\cos\theta\, \ddot\theta &= -c \dot p -
      ml \sin\theta\, \dot\theta^2 + F \\
    (J+ml^2)\ddot\theta - m l \cos\theta\, \ddot p &= -\gamma +
    \dot\theta mgl\sin\theta,
  \endaligned
\end{equation*}
\end{document}