zz晓枫
幼苗
共回答了13个问题采纳率:69.2% 举报
题目应该是这样吧:(1-1/2+1/3-1/4+1/5-...+1/99-1/100)/[1/(1+101)+1/(2+102)+1/(3+103)+...+1/(49+149)+1/(50+150)
1-1/2+1/3-1/4+...+1/99-1/100
=拆
1/(1*2)=1-1/2
1/(2*3)=1/2-1/3
...
每一个都拆开
1-1/2-1/2+1/3-1/3+1/4.-1/99+1/100
=1/100 这是分子的化简值;
分母=1/102+1/104+1/106+.+1/200
=1/2*(1/51+1/52+1/53+.+1/100)
= 1/200
分子/分母=2
1年前
11