找规律计算:1/2+1/6+1/12+1/20+…+1/9900=_.

问题描述:

找规律计算:

1
2
+
1
6
+
1
12
+
1
20
+…+
1
9900
=______.

1
2
+
1
6
+
1
12
+
1
20
+…+
1
9900

=(1-
1
2
)+(
1
2
-
1
3
)+(
1
3
-
1
4
)+(
1
4
-
1
5
)+…+(
1
99
-
1
100
),
=1-
1
100

=
99
100