1/1*2+1/2*3+1/3*4+1/4*5+.....+1/199*200要简便

来源:百度知道 编辑:UC知道 时间:2024/05/25 08:55:10
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1/1*2+1/2*3+1/3*4+1/4*5+.....+1/199*200
=1-1/2+1/2-1/3+1/3-1/4+------+1/199-1/200
=1-1/200
=199/200

1/[n(n+1)]=1/n-1/(n+1)
原式=(1-1/2)+(1/2-1/3)+...+(1/199-1/200)
=1-1/200
=199/200

=(1-1/2)+(1/2-1/3)+(1/3-1/4)...(1/199-1/200)
=1-1/200
=199/200

原式=(1-1/2)+(1/2-1/3)+(1/3-1/4)+....+(1/199-1/200)=1-1/2+1/2-1/3+1/3-.....-1/199+1/199-1/200=199/200

原式=(1-1/2)+(1/2-1/3)+(1/3-1/4)+…+(1/199-1/200)=1-1/200=199/200

1-1/2+1/2-1/3+1/3-1/4+.....+1/199-1/200=199/200