题目内容
1
-
+
-
+
-
.
| 1 |
| 3 |
| 7 |
| 12 |
| 9 |
| 20 |
| 11 |
| 30 |
| 13 |
| 42 |
| 15 |
| 56 |
分析:把
拆分为
+
,
拆分为
+
,
拆分为
+
,
拆分为
+
,
拆分为
+
,然后去掉括号,进行抵销解答即可.
| 7 |
| 12 |
| 1 |
| 3 |
| 1 |
| 4 |
| 9 |
| 20 |
| 1 |
| 4 |
| 1 |
| 5 |
| 11 |
| 30 |
| 1 |
| 5 |
| 1 |
| 6 |
| 13 |
| 42 |
| 1 |
| 6 |
| 1 |
| 7 |
| 15 |
| 56 |
| 1 |
| 7 |
| 1 |
| 8 |
解答:解:1
-
+
-
+
-
,
=1
-(
+
)+(
+
)-(
+
)+(
+
)-(
+
),
=1
-
-
+
+
-
-
+
+
-
-
,
=1
-
-
,
=
.
| 1 |
| 3 |
| 7 |
| 12 |
| 9 |
| 20 |
| 11 |
| 30 |
| 13 |
| 42 |
| 15 |
| 56 |
=1
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 4 |
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 6 |
| 1 |
| 6 |
| 1 |
| 7 |
| 1 |
| 7 |
| 1 |
| 8 |
=1
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 4 |
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 6 |
| 1 |
| 6 |
| 1 |
| 7 |
| 1 |
| 7 |
| 1 |
| 8 |
=1
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 8 |
=
| 7 |
| 8 |
点评:根据给出的分数的特点进行拆分是解答此题的关键所在.
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