计算:1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)+…+1/(x+100)(x+101)

问题描述:

计算:

1
(x+1)(x+2)
+
1
(x+2)(x+3)
+
1
(x+3)(x+4)
+…+
1
(x+100)(x+101)

1
(x+1)(x+2)
+
1
(x+2)(x+3)
+
1
(x+3)(x+4)
+…+
1
(x+100)(x+101)

=
1
x+1
-
1
x+2
+
1
x+2
-
1
x+3
+…+
1
x+100
-
1
x+101

=
1
x+1
-
1
x+101

=
100
(x+1)(x+101)