题目内容
计算:
+
+
+…+
.
| 4 |
| 1×3×5 |
| 4 |
| 3×5×7 |
| 4 |
| 5×7×9 |
| 4 |
| 2011×2013×2015 |
考点:有理数的混合运算
专题:
分析:首先把每一项拆分
=
(1-
-
+
),
=
(
-
-
+
)…进一步抵消计算即可.
| 4 |
| 1×3×5 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 5 |
| 4 |
| 3×5×7 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 7 |
解答:解:原式=
×(1-
-
+
+
-
-
+
+
-
-
+
+…+
-
-
+
)
=
×(1-
-
+
)
=
-
=
.
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 7 |
| 1 |
| 5 |
| 1 |
| 7 |
| 1 |
| 7 |
| 1 |
| 9 |
| 1 |
| 2011 |
| 1 |
| 2013 |
| 1 |
| 2013 |
| 1 |
| 2015 |
=
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 2013 |
| 1 |
| 2015 |
=
| 1 |
| 3 |
| 1 |
| 2013×2015 |
=
| 1352064 |
| 4056195 |
点评:此题考查有理数的混合运算,注意拆分是正确计算的前提.
练习册系列答案
相关题目