\documentclass[12pt]{article}
\usepackage{amssymb,amsmath,amscd,concmath,amsfonts}
\usepackage{color}
\pagestyle{empty}
\begin{document}
\begin{equation*}
  K = \begin{bmatrix}-15.6 & 1730 & -50.1 & 443 \end{bmatrix}.
\end{equation*}
\end{document}