题目内容
请先阅读下列一组内容,然后解答问题:
因为:
=1-
,
=
-
,
=
-
,…,
=
-
,
所以:
+
+
+…+
=(1-
)+(
-
)+(
-
)+…+(
-
)=1-
+
-
+
-
+…+
-
=1-
=
.
计算:(1)
+
+
+…+
(2)
+
+
+…+
.
因为:
| 1 |
| 1×2 |
| 1 |
| 2 |
| 1 |
| 2×3 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3×4 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 9×10 |
| 1 |
| 9 |
| 1 |
| 10 |
所以:
| 1 |
| 1×2 |
| 1 |
| 2×3 |
| 1 |
| 3×4 |
| 1 |
| 9×10 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 9 |
| 1 |
| 10 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 9 |
| 1 |
| 10 |
| 1 |
| 10 |
| 9 |
| 10 |
计算:(1)
| 1 |
| 1×2 |
| 1 |
| 2×3 |
| 1 |
| 3×4 |
| 1 |
| 2013×2014 |
(2)
| 1 |
| 1×3 |
| 1 |
| 3×5 |
| 1 |
| 5×7 |
| 1 |
| 49×51 |
(1)原式=1-
+
-
+
-
+…+
-
=1-
=
;
(2)原式=
×(1-
+
-
+
-
+…+
-
)=
.
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 2013 |
| 1 |
| 2014 |
| 1 |
| 2014 |
| 2013 |
| 2014 |
(2)原式=
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 7 |
| 1 |
| 49 |
| 1 |
| 51 |
| 25 |
| 51 |
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