初一 数学 谢谢老师 请详细解答,谢谢! (18 16:23:7)

|ab+2|+|a+1|=0
=>a+1=0;ab+2=0
=>a=-1,b=2

解析：任何数的绝对值都是非负数，两个非负数相加等于0，也就说明，这两个数都为0，所以就可以得出a和b的值

把a、b代入得：

1/(a-1)(b+1)+1/(a-2)(b+2)+...+1/(a-2009)(b+2009).
=-1/2+1/3+(-1/3)+1/4+……+1/2010-1/2009+1/2011-1/2010
=-1/2+1/2011
=-1005/2011

|ab+2|+|a+1|=0
=>a+1=0;ab+2=0
=>a=-1,b=2

1/(a-1)(b+1)+1/(a-2)(b+2)+...+1/(a-2009)(b+2009).
=-1/2+1/3+(-1/3)+1/4+……+1/2010-1/2009+1/2011-1/2010
=-1/2+1/2011
=-1005/2011