\documentclass{book} \usepackage{amssymb,amsmath} %\usepackage[thmmarks,framed]{ntheorem} \usepackage{xepersian} \begin{document} داریم \begin{align*} \langle v-w,u\rangle &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \\ &=\langle v-w,\sum_{i=1}n a_iu_i\rangle \end{align*} \end{document}