题目内容
1
+2
+3
+4
+5
+6
+7
+8
=?
| 1 |
| 2 |
| 1 |
| 6 |
| 1 |
| 12 |
| 1 |
| 20 |
| 1 |
| 30 |
| 1 |
| 42 |
| 1 |
| 56 |
| 1 |
| 72 |
1
+2
+3
+4
+5
+6
+7
+8
,
=(1+2+3+…+8)+(
+
+
+…+
),
=36+(1-
+
-
+
-
+…+
-
),
=36+(1-
),
=36+
,
=36
.
| 1 |
| 2 |
| 1 |
| 6 |
| 1 |
| 12 |
| 1 |
| 20 |
| 1 |
| 30 |
| 1 |
| 42 |
| 1 |
| 56 |
| 1 |
| 72 |
=(1+2+3+…+8)+(
| 1 |
| 2 |
| 1 |
| 6 |
| 1 |
| 12 |
| 1 |
| 72 |
=36+(1-
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 8 |
| 1 |
| 9 |
=36+(1-
| 1 |
| 9 |
=36+
| 8 |
| 9 |
=36
| 8 |
| 9 |
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