Latex code throwing 1.19.2.1 Pandoc off

sample.tex

\tolerance =10000
\documentclass[11pt]{article}
\usepackage{epsfig}
\renewcommand{\baselinestretch}{1.5}
\makeatletter
\@addtoreset{equation}{section}
\renewcommand{\theequation}{\thesection.\arabic{equation}}
\makeatother
\oddsidemargin=0in
\evensidemargin=0in
\textwidth=6.45in
\headsep=0pt
\topmargin=0pt
\textheight=9.1in
\newcommand{\be}{\begin{equation}}
\newcommand{\ee}{\end{equation}}
\newcommand{\bea}{\begin{eqnarray}}
\newcommand{\eea}{\end{eqnarray}}
\newcommand{\mbf}[1]{\mbox{\boldmath$#1$}}
\begin{document}

\be
q \sim \sum_{i=1}^{N} \frac{X_i^2}{\sigma_i^2},
\quad
\lambda = \sum_{i=1}^{N} \frac{\mu_i^2}{\sigma_i^2},
\label{e1}
\ee

\end{document}