已知|a-1|+(ab-2)²=0求1/(a+1)(b+1)+1/(a+2)(b+2)到1/(a+2008)(b+2008)的初中一年级

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已知|a-1|+(ab-2)²=0求1/(a+1)(b+1)+1/(a+2)(b+2)到1/(a+2008)(b+2008)的初中一年级已知|a-1|+(ab-2)²=0求1/(a

已知|a-1|+(ab-2)²=0求1/(a+1)(b+1)+1/(a+2)(b+2)到1/(a+2008)(b+2008)的初中一年级
已知|a-1|+(ab-2)²=0求1/(a+1)(b+1)+1/(a+2)(b+2)到1/(a+2008)(b+2008)的
初中一年级

已知|a-1|+(ab-2)²=0求1/(a+1)(b+1)+1/(a+2)(b+2)到1/(a+2008)(b+2008)的初中一年级
|a-1|+(ab-2)²=0,
a-1=0,ab-2=0,联立解得:a=1,b=2;
1/(a+1)(b+1)+1/(a+2)(b+2)+···+1/(a+2008)(b+2008)
=1/(2×3)+1/(3×4)+···+1/(2009×2010)
用裂项相消法,得
=1/2-1/3+1/3-1/4+···+1/2009-1/2010
=1/2-1/2010
=1004/2010
=502/1005

很明显,a=1 ,b=2
那么,你就带进去算吧

|a-1|+(ab-2)²=0
因为|a-1|>=0,(ab-2)²>=0
所以a-1=0,ab-2=0
a=1,b=2
1/(a+1)(b+1)+1/(a+2)(b+2)加到1/(a+2008)(b+2008)
=1/(2*3)+1/(3*4)+..+1/(2009*2010)
=1/2-1/3+1/3-1/4+..+-1/2009+1/2009-1/2010
=1/2-1/2010
=502/1005