5/6-7/12+9/20-11/30+.(n-1)*n/(n-1)+n-n+(n+1)/n*(n+1)=?今天就要!~~O(∩_∩)O谢谢了

5/6-7/12+9/20-11/30+.(n-1)*n/(n-1)+n-n+(n+1)/n*(n+1)=?今天就要!~~O(∩_∩)O谢谢了
5/6-7/12+9/20-11/30+.(n-1)*n/(n-1)+n-n+(n+1)/n*(n+1)=?
今天就要!~~O(∩_∩)O谢谢了

5/6-7/12+9/20-11/30+.(n-1)*n/(n-1)+n-n+(n+1)/n*(n+1)=?今天就要!~~O(∩_∩)O谢谢了
5/6-7/12+9/20-11/30+.(n-1)*n/(n-1)+n-n+(n+1)/n*(n+1)
=（1/2+1/3）-(1/3+1/4)+(1/4+1/5)-(1/5+1/6)+...+(1/n+1/(n+1))
=1/2+1/3-1/3-1/4+1/4+1/5-...+1/n+1/(n+1)
=1/2+1/(n+1)
=(n+1+2)/2(n+1)
=(n+3)/2(n+1);
很高兴为您解答,skyhunter002为您答疑解惑
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