问题标题:
七年级数学题|ab-2|与|b-1|互为相反数,试求代数式:1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+...+1/(a+2004)(b+2004)的值
问题描述:
七年级数学题
|ab-2|与|b-1|互为相反数,试求代数式:
1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+...+1/(a+2004)(b+2004)的值
李明星回答:
/ab-2/与/b-1/互为相反数ab-2=0b-1=0ab=2b=1,a=21/ab+1/(a+2)(b+2)+...+1/(a+2009)(b+2009)=1/2+1/4*3+------+1/2011*2010=1/2(1-1/2+1/2-1/3+-----+1/2010-1/2011)=1/2(1-1/2011)=(1/2)*(2010/2011)=1005...
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