\documentclass{report}
\usepackage{amsthm,amssymb,amsmath}
\usepackage{systeme}
\usepackage{multicol}
\usepackage{xepersian}
\makeatletter
\@ifundefined{Umathcode}{\let\Umathcode\XeTeXmathcode}{}
\@ifundefined{Umathchardef}{\let\Umathchardef\XeTeXmathchardef}{}
\makeatother

\begin{document}
\begin{multicols}{2}
\begin{enumerate}
\item
$\sysdelim..\systeme{x+y+3z=5,2x-y+4z=115,-y+z=3.}$
\item
$\sysdelim..\systeme[xyzu]{x-2y+z+2u=-2,2x+3y-z-5u=9,4x-y+z-u={}5,5x-3y+2z+u={}3.}$
\end{enumerate}
\end{multicols}
\end{document}