(1+1/2+1/3+1/4)÷(1/2+1/3+1/4+1/5)= 要用简便方法计算
问题描述:
(1+1/2+1/3+1/4)÷(1/2+1/3+1/4+1/5)= 要用简便方法计算
答
(1+1/2+1/3+1/4)÷(1/2+1/3+1/4+1/5)
=[(1/2+1/3+1/4+1/5)+4/5]÷(1/2+1/3+1/4+1/5)=1+4/5/(1/2+1/3+1/4+1/5)=1+4/5/(30+20+15+12)/60=1+4/5*60/77=1+48/77=125/77