紫壁樵歌
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√(a-1)+(ab-2)²=0
√(a-1)>=0,(ab-2)²>=0
所以a-1=0,ab-2=0
a=1,
b=2
所以1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+........+1/(a+2013)(b+2013)
=1/2+1/(2*3)+1/(3*4)+.....+1/(2014*2015)
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+.....+(1/2014-1/2015)
=1-1/2015
=2014/2015
1年前
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