已知lab-2|与|b-1|互为相反数,试求代数式1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)…+1/(a+2014)(b+2014)的值.

问题描述:

已知lab-2|与|b-1|互为相反数,试求代数式1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)…+1/(a+2014)(b+2014)的值.

互为相反数的和等于0
|ab-2|+|b-1|=0 两个非负数的和等于0,则这两个非负数都等于0
ab-2=0 且 b-1=0
解得 a=2 ,b=1
原式=1/(1×2) +1/(2×3) +1/(3×4)+……+1/(2015×2016)
=1 -1/2 +1/2-1/3 +1/3-1/4 +……+1/2015-1/2016
=1 -1/2016
=2015/2016