\documentclass[a4paper,10pt,twoside]{book}

\usepackage{amsthm}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{ptext}
\usepackage[top=25mm, bottom=25mm, left=35mm, right=25mm,showframe]{geometry}
\usepackage{setspace}
\renewcommand{\baselinestretch}{1.5}


\usepackage{xepersian}
\settextfont[Scale=1.4]{XB Zar}
\setlatintextfont[Scale=1.2]{Times New Roman}


\begin{document}
	\baselineskip=1.2cm
	\chapter{اول}
	\section{اول}
	\ptext[1-10]
	\begin{equation}
	\int_{0}^{\infty}2^xdx
	\end{equation}
	\section{دوم}
	\ptext[1-10]
\end{document}