问题 解答题
请观察并计算下列各题,你发现了什么?
1
2
×
1
3
=
1
3
×
1
4
=
1
4
×
1
5
=
1
10
×
1
11
=
1
2
-
1
3
=
1
3
-
1
4
=
1
4
-
1
5
=
1
10
-
1
11
=
答案

1
2
×
1
3
=
1
6

1
3
×
1
4
=
1
12

1
4
×
1
5
=
1
20

1
10
×
1
11
=
1
110

1
2
-
1
3
=
1
6

1
3
-
1
4
=
1
12

1
4
-
1
5
=
1
20

1
10
-
1
11
=
1
110

发现规律:

1
n
×
1
n+1
=
1
n
-
1
n+1

单项选择题
填空题