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(1)计算:1x−1x+1=,1x+1−1x+2=,1x+2−1x+3=;(2)计算:1x(x+1)+1(x+1)(x+2)+1(x+2)(x+3)+…+1(x+2013)(x+2014),当x=1时,求该代数式的值.

题目详情
(1)计算:
1
x
1
x+1
=______,
1
x+1
1
x+2
=______,
1
x+2
1
x+3
=______;
(2)计算:
1
x(x+1)
+
1
(x+1)(x+2)
+
1
(x+2)(x+3)
+…+
1
(x+2013)(x+2014)
,当x=1时,求该代数式的值.
▼优质解答
答案和解析
(1)
1
x
-
1
x+1
=
1
x(x+1)
1
x+1
-
1
x+2
=
1
(x+1)(x+2)
1
x+2
-
1
x+3
=
1
(x+2)(x+3)

(2)原式=
1
x
-
1
x+1
+
1
x+1
-
1
x+2
+…+
1
x+2013
-
1
x+2014
=
1
x
-
1
x+2014
=
2014
x(x+2014)

当x=1时,原式=
2014
2015

故答案为:(1)
1
x(x+1)
1
(x+1)(x+2)
1
(x+2)(x+3)