题目内容
因为1-
=
，
-
=
，
-
=
，
所以
+
=1-
+
-
=1-
=
；
+
+
=1-
+
-
+
-
=1-
=
；
根据规律求：
+
+
= ．
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 6 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 12 |
所以
| 1 |
| 2 |
| 1 |
| 6 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
=1-
| 1 |
| 3 |
=
| 2 |
| 3 |
| 1 |
| 2 |
| 1 |
| 6 |
| 1 |
| 12 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
=1-
| 1 |
| 4 |
=
| 3 |
| 4 |
根据规律求：
| 1 |
| 12 |
| 1 |
| 20 |
| 1 |
| 30 |
考点：分数的巧算
专题：计算问题（巧算速算）
分析：根据给出的例子，把每个分数拆成两个分数相减的形式，然后通过加减相互抵消，求得结果．
解答：
解：
+
+
=
-
+
-
+
-
=
-
=
故答案为：
．
| 1 |
| 12 |
| 1 |
| 20 |
| 1 |
| 30 |
=
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 4 |
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 6 |
=
| 1 |
| 3 |
| 1 |
| 6 |
=
| 1 |
| 6 |
故答案为：
| 1 |
| 6 |
点评：仔细观察给出的例子，找出规律，据规律解答．
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