1/5÷[（2/3+1/5）×1/13]×2/3这道算式=1/5÷〔(10/15+3/15)*1/13〕*2/3=1/5÷(13/15*1/13)*2/3=1/5÷1/15*2/3=1/5* 15*2/3=3*2/3=2
