Mein LaTeX-Forum

\documentclass[a4paper,12pt]{article}
\usepackage[latin1]{inputenc}
    \usepackage{amsmath}                                                                  
\usepackage{mathtools}
\numberwithin{equation}{section}

\begin {document}

\begin{align}
\sum_{k=1}^K=(tb_k\cdot X_{kt}+tr_k\cdot \gamma_{kt})\leq{b_t}&
t=1,2,\dots,T, k=1,2,\dots,K
\end{align}

\end{document}