问题 解答题
已知:|ab-2|+(b+1)2=0,
求:(1)a,b的值;
(2)b2011-(
a
2
)2011
的值.
(3)
1
ab
+
1
(a-1)(b-1)
+
1
(a-2)(b-2)
+…+
1
(a-2012)(b-2012)
的值.
答案

(1)∵|ab-2|+(b+1)2=0,

∴ab-2=0,b+1=0,

解得:a=-2,b=-1;

(2)当a=-2,b=-1时,b2011-(

a
2
)2011=(-1)2011-(
-2
2
2011

=-1-(-1)

=0.

(3)当a=-2,b=-1时,

1
ab
+
1
(a-1)(b-1)
+
1
(a-2)(b-2)
+…+
1
(a-2012)(b-2012)

=

1
(-2)×(-1)
+
1
(-3)×(-2)
+
1
(-4)×(-3)
+…+
1
(-2014)×(-2013)

=1-

1
2
+
1
2
-
1
3
+
1
3
-
1
4
+…+
1
2013
-
1
2014

=1-

1
2014

=

2013
2014

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