\usepackage[inner=3cm,outer=2.5cm]{geometry}
یا
\oddsidemargin و \evensidemargin تعیین کنید.
یا:
\documentclass[twoside]{article}
\usepackage[hmarginratio=3:4]{geometry}
The hmarginratio option sets the horizontal margin ratio to 3:4 (default for two sided documents is 2:3). Easy as that!