\documentclass[12pt]{article}
\usepackage{amssymb,amsmath,amscd,concmath,amsfonts}
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\begin{document}
\begin{equation*}
  u=k_pe+k_d\frac{de}{dt}=k\bigl(e+T_d\frac{de}{dt}\bigr),
\end{equation*}
\end{document}