计算:1/(1*3)+1/(3*5)+……+1/(99*101)*是乘.

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计算:1/(1*3)+1/(3*5)+……+1/(99*101)
*是乘.

1/(1*3)+1/(3*5)+……+1/(99*101)
=1/2*(1-1/3)+1/2*(1/3-1/5)+.+1/2*(1/99-1/101)
=1/2*(1-1/3+1/3-1/5+.+1/99-1/101)
=1/2*(1-1/101)
=1/2*100/101
=50/101

50/101

把每个分式拆成类似1/(1*3)=1/2(1/3-1/5)
然后加起来有很多可以消

50/101
算法如下:
1/(1*3)+1/(3*5)+……+1/(99*101)
=1/2*(1-1/3)+1/2*(1/3-1/5)+......+1/2*(1/99-1/101)
=1/2*(1-1/3+1/3-1/5+......+1/99-1/101)
=1/2*(1-1/101)
=1/2*100/101
=50/101