初一的数学问题
已知|ab+2|+|a+1|=0,
求1/(a-1)(b+1)+1/(a-2)(b+2)+.....+1/(a-2006)(b+2006)
参考答案:解:由已知得 a=-1,b=2,
代入得1/(-2×3)+1/(-3×4)...1/(-2007×2008)即
-(1/2-1/3+1/3-1/4+...+1/2007-1/2008)
=-(1/2-1/2008)=-1003/2008
已知|ab+2|+|a+1|=0,
求1/(a-1)(b+1)+1/(a-2)(b+2)+.....+1/(a-2006)(b+2006)
参考答案:解:由已知得 a=-1,b=2,
代入得1/(-2×3)+1/(-3×4)...1/(-2007×2008)即
-(1/2-1/3+1/3-1/4+...+1/2007-1/2008)
=-(1/2-1/2008)=-1003/2008