1/2+1/6+1/12+1/20+1/30+...+1/9702+1/9900
题目
1/2+1/6+1/12+1/20+1/30+...+1/9702+1/9900
答案
1/2+1/6+1/12+1/20+1/30+...+1/9702+1/9900
=1/(1*2)+1/(2*3)+1/(4*5)+1/(5*6)+……
+1/(98*99)+1/(99*100)
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+……+(1/98-1/99)+(1/99-1/100)
=1-1/100
=99/100
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