题目内容
若
+(ab-2)2=0,那么
+
+…+
的值是
.
| a-1 |
| 1 |
| a |
| 1 |
| (a+1)(b+1) |
| 1 |
| (a+2010)(b+2010) |
| 3017 |
| 2012 |
| 3017 |
| 2012 |
分析:由已知等式左边为两个非负数之和,利用两非负数之和为0,两非负数分别为0列出关于a与b的方程,联立求出a与b的值,将求出的a与b的值代入所求式子中,利用拆项法变形,抵消合并后即可求出值.
解答:解:∵
+(ab-2)2=0,
∴a-1=0且ab-2=0,
解得:a=1,b=2,
∴
+
+…+
=1+
+
+…+
=1+
-
+
-
+…+
-
=1+
-
=
.
故答案为:
| a-1 |
∴a-1=0且ab-2=0,
解得:a=1,b=2,
∴
| 1 |
| a |
| 1 |
| (a+1)(b+1) |
| 1 |
| (a+2010)(b+2010) |
=1+
| 1 |
| 2×3 |
| 1 |
| 3×4 |
| 1 |
| 2011×2012 |
=1+
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 2011 |
| 1 |
| 2012 |
=1+
| 1 |
| 2 |
| 1 |
| 2012 |
=
| 3017 |
| 2012 |
故答案为:
| 3017 |
| 2012 |
点评:此题考查了分式的化简求值,以及非负数的性质,根据题意得出
=
-
是解本题的关键.
| 1 |
| n(n+1) |
| 1 |
| n |
| 1 |
| n+1 |
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