\documentclass{article}
\usepackage{amsthm,amssymb,amsmath}
\usepackage{xepersian}
\begin{document}
\[
\begin{array}{{l@{=}rl@{=}rl@{=}r}}
r_0& = q_1r_1 + r_2,& 0<r_2<r_1\\
r_1& = q_1r_1 + r_3,& 0<r_3<r_2\\
\vdots&\vdots&\vdots&\vdots\\
 r_{m-2}& = q_{m-1}r_{m-1} + r_m,&0 < r_m < r_m-1\\
 r_{m-1}& =q_{m}r_m
\end{array}.
\]
\end{document}