已知|ab+2|+|a+1|=0,求1/（a-1)(b+1)+1/(a-2)(b+2).+1/(a-2004)(b+2004)的值
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已知|ab+2|+|a+1|=0,求1/（a-1)(b+1)+1/(a-2)(b+2).+1/(a-2004)(b+2004)的值
已知|ab+2|+|a+1|=0,求1/（a-1)(b+1)+1/(a-2)(b+2).+1/(a-2004)(b+2004)的值
已知|ab+2|+|a+1|=0,求1/（a-1)(b+1)+1/(a-2)(b+2).+1/(a-2004)(b+2004)的值
绝对值大于等于0,相加等于0,若有一个大于0,则另一个小于0,不成立
所以两个都等于0
所以ab+2=0,a+1=0
a=-1,ab=-2,b=-2/a=2
所以1/(a-1)(b+1)+1/(a-2)(b+2)+……+1/(a-2004)(b+2004)
=1/(-2)*3+(-3)*4+……+1/(-2005)*2006
=-(1/2*3+1/3*4+……+1/2005*2006)
=-[(1/2-1/3)+(1/3-1/4)+……+(1/2005-1/2006)
=-(1/2-1/2006)
=-501/1003
ab+2=0,a+1=0
a=-1,b=2
1/（a-1)(b+1)+1/(a-2)(b+2)......+1/(a-2004)(b+2004)
=1/(-6)+1/(-12)+……+1/[-2005*2006]
=-[(1/2-1/3)+(1/3-1/4)+……+(1/2005-1/2006)]
=-(1/2-1/2006)
=-1002/2006
=-501/1003
|ab+2| + |a+1| = 0
因为绝对值都是>=0,
所以：ab+2=0,a+1=0
a=-1,b=2.
1/(a-1)(b+1) + 1/(a-2)(b+2) + ... + 1/(a-2004)(b+2004)
=1/(-2*3)+1/(-3*4)+...+1/(-2005*2006)
=-1*[1/(2*3)+1/(3*4)+1/(4*...
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|ab+2| + |a+1| = 0
因为绝对值都是>=0,
所以：ab+2=0,a+1=0
a=-1,b=2.
1/(a-1)(b+1) + 1/(a-2)(b+2) + ... + 1/(a-2004)(b+2004)
=1/(-2*3)+1/(-3*4)+...+1/(-2005*2006)
=-1*[1/(2*3)+1/(3*4)+1/(4*5)+...+1/(2005*2006)]
=-1*[(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+...+(1/2005-1/2006)]
=-1*(1/2-1/2006)
=-1002/2006
=-501/1003
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