题目内容
化简求值:
+
+
+…+
+
,其中a=2006.
| 1 |
| a(a+2) |
| 1 |
| (a+2)(a+4) |
| 1 |
| (a+4)(a+6) |
| 1 |
| (a+2002)(a+2004) |
| 1 |
| (a+2004)(a+2006) |
考点:分式的化简求值
专题:
分析:根据
=
(
-
),
=
(
-
),…,
=
(
-
),可得原式的值为
(
-
),再代入a=2006即可.
| 1 |
| a(a+2) |
| 1 |
| 2 |
| 1 |
| a |
| 1 |
| a+2 |
| 1 |
| (a+2)(a+4) |
| 1 |
| 2 |
| 1 |
| a+2 |
| 1 |
| a+4 |
| 1 |
| (a+2004)(a+2006) |
| 1 |
| 2 |
| 1 |
| a+2004 |
| 1 |
| a+1006 |
| 1 |
| 2 |
| 1 |
| a |
| 1 |
| a+2006 |
解答:解:∵
=
(
-
),
=
(
-
),…,
=
(
-
),
∴原式=
(
-
+
-
+…+
-
),
(
-
),
∵a=2006,
∴原式=
(
-
)
=
×
=
.
| 1 |
| a(a+2) |
| 1 |
| 2 |
| 1 |
| a |
| 1 |
| a+2 |
| 1 |
| (a+2)(a+4) |
| 1 |
| 2 |
| 1 |
| a+2 |
| 1 |
| a+4 |
| 1 |
| (a+2004)(a+2006) |
| 1 |
| 2 |
| 1 |
| a+2004 |
| 1 |
| a+1006 |
∴原式=
| 1 |
| 2 |
| 1 |
| a |
| 1 |
| a+2 |
| 1 |
| a+2 |
| 1 |
| a+4 |
| 1 |
| a+2004 |
| 1 |
| a+1006 |
| 1 |
| 2 |
| 1 |
| a |
| 1 |
| a+2006 |
∵a=2006,
∴原式=
| 1 |
| 2 |
| 1 |
| 2006 |
| 1 |
| 4012 |
=
| 1 |
| 2 |
| 1 |
| 4012 |
=
| 1 |
| 8024 |
点评:本题考查了分式的化简求值,把分式中的
化为
(
-
)是解题的关键.
| 1 |
| a(a+2) |
| 1 |
| 2 |
| 1 |
| a |
| 1 |
| a+2 |
练习册系列答案
相关题目
| A、 |
| B、 |
| C、 |
| D、 |