szg4530396
幼苗
共回答了19个问题采纳率:94.7% 举报
(1+1/2+1/3+1/4)*(1/2+1/3+1/4+1/6)-(1+1/2+1/3+1/4+1/5)*(1/2+1/3+1/4)
=(1+1/2+1/3+1/4)*(1/2+1/3+1/4+1/6)-(1+1/2+1/3+1/4)*(1/2+1/3+1/4)-(1/5)*(1/2+1/3+1/4)
=(1+1/2+1/3+1/4)*(1/6)-(1/5)*(1/2+1/3+1/4)
=1/6+(1/2+1/3+1/4)*(1/6)-(1/5)*(1/2+1/3+1/4)
=1/6+(1/2+1/3+1/4)*(-1/30)
=47/360
1年前
1