计算: (1)x/x−1-x+3/x2−1•x2+2x+1x+3;(2)(1/x−2-1)÷3−xx2−4.

问题描述:

计算:
(1)

x
x−1
-
x+3
x2−1
x2+2x+1
x+3
;(2)(
1
x−2
-1)÷
3−x
x2−4

(1)原式=

x
x−1
x+3
(x+1)(x−1)
(x+1)2
x+3

=
x
x−1
x+1
x−1

=-
1
x−1

(2)原式=
3−x
x−2
÷
3−x
(x+2)(x−2)

=
3−x
x−2
(x+2)(x−2)
3−x

=x+2.