由|ab-2|与(b-1)2知道b = 1a = 2b =a - 11/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+...+1/(a+2005(b+2005)= 1/a(a-1) + 1/(a+1)a + 1/(a+1)(a+2)+...+1/(a+2004)(a+2005)= 1/(a-1) - 1/a + 1/a - 1/(a+1)+...+1/(a+2004) - 1/...