题目内容
（2011?长春模拟）（
+
+
+…+
）+（
+
+
+…+
）+（
+
+
+…+
）+…+（
+
）+
．
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 30 |
| 2 |
| 3 |
| 2 |
| 4 |
| 2 |
| 5 |
| 2 |
| 30 |
| 3 |
| 4 |
| 3 |
| 5 |
| 3 |
| 6 |
| 3 |
| 30 |
| 28 |
| 29 |
| 28 |
| 30 |
| 29 |
| 30 |
分析：通过观察，算式中的数字具有一定的特点和规律，先把
拿出来，剩下的数运用加法交换律和结合律，把分母相同的分数加在一起，通过计算得解．
| 1 |
| 2 |
解答：解：（
+
+
+…+
）+（
+
+
+…+
）+（
+
+
+…+
）+…+（
+
）+
，
=
+（
+
）+（
+
+
）+…+（
+
+…+
），
=
+
+
+…+
，
=
，
=
，
=
．
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 30 |
| 2 |
| 3 |
| 2 |
| 4 |
| 2 |
| 5 |
| 2 |
| 30 |
| 3 |
| 4 |
| 3 |
| 5 |
| 3 |
| 6 |
| 3 |
| 30 |
| 28 |
| 29 |
| 28 |
| 30 |
| 29 |
| 30 |
=
| 1 |
| 2 |
| 1 |
| 3 |
| 2 |
| 3 |
| 1 |
| 4 |
| 2 |
| 4 |
| 3 |
| 4 |
| 1 |
| 30 |
| 2 |
| 30 |
| 29 |
| 30 |
=
| 1 |
| 2 |
| 2 |
| 2 |
| 3 |
| 2 |
| 29 |
| 2 |
=
| (1+29)×29÷2 |
| 2 |
=
| 30×29 |
| 4 |
=
| 435 |
| 2 |
点评：此题考查了学生灵活运用所学知识，进行巧妙解答的能力．
练习册系列答案
相关题目
