已知|ab-2|与|b-1|互为相反数,求下列代数式的值: 1/ab+1/(a+1)×(b+1)+1/(a+2)×(b+2)+…+1/(a+2012)×(b+2012).
问题描述:
已知|ab-2|与|b-1|互为相反数,求下列代数式的值:
+1 ab
+1 (a+1)×(b+1)
+…+1 (a+2)×(b+2)
. 1 (a+2012)×(b+2012)
答
根据题意得:|ab-2|+|b-1|=0,
解得:a=2,b=1,
则原式=
+1 1×2
+…+1 2×3
=1-1 2013×2014
+1 2
-1 2
+…+1 3
-1 2013
=1-1 2014
=1 2014
.2013 2014