题目内容
观察下面的变形规律:
=1-
;
=
-
;
=
-
;…
解答下面的问题:
(1)计算
=______;
(2)若n为正整数,请你猜想
=______;
(3)利用你的结论求:
+
+
+…+
.
1 |
1×2 |
1 |
2 |
1 |
2×3 |
1 |
2 |
1 |
3 |
1 |
3×4 |
1 |
3 |
1 |
4 |
解答下面的问题:
(1)计算
1 |
5×6 |
(2)若n为正整数,请你猜想
1 |
n(n+1) |
(3)利用你的结论求:
1 |
1×2 |
1 |
2×3 |
1 |
3×4 |
1 |
9×10 |
(1)
=
-
;
(2)
=
-
;
(3)
+
+
+…+
=1-
+
-
+…+
-
=1-
=
.
故答案为:
-
;
-
.
1 |
5×6 |
1 |
5 |
1 |
6 |
(2)
1 |
n(n+1) |
1 |
n |
1 |
n+1 |
(3)
1 |
1×2 |
1 |
2×3 |
1 |
3×4 |
1 |
9×10 |
=1-
1 |
2 |
1 |
2 |
1 |
3 |
1 |
9 |
1 |
10 |
=1-
1 |
10 |
=
9 |
10 |
故答案为:
1 |
5 |
1 |
6 |
1 |
n |
1 |
n+1 |
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