/ http://www.slideshare.net/images/logo.gif / ºÝºÝߣShare feed for ºÝºÝߣshows by User: hoangnguyenngocbk https://cdn.slidesharecdn.com/profile-photo-hoangnguyenngocbk-48x48.jpg?cb=1524276073 NghÄ© phức tạp, làm Ä‘Æ¡n giản