问题 解答题
(1)
2
x-1
-
3
x+1
=
x+3
x2-1

(2)
x-3
x-1
-
x-5
x-7
=1-
x2-2
x2-8x+7
答案

(1)原方程可化为:

2x+2
x2-1
3x-3
x2-1
x+3
x2-1

整理得:

-x+5
x2-1
x+3
x2-1

移项得:

x+3
x2-1
x-5
x2-1
=0,

方程的两边同乘(x2-1)得:2x-2=0,解得x=1.

检验:把x=1代入x2-1=1-1=0,

∴原方程无解.

(2)原方程可化为:

x-3
x-1
x-5
x-7
=1- 
x2-2
(x-1)(x-7)

整理并通分得:

(x-3)(x-7)
(x-1)(x-7)
(x-5)(x-1)
(x-1)(x-7)
+
x2-2
(x-1)(x-7)
=1,

化简并整理得:x2-4x+14=x2-8x+7,

解得:4x=-7,x=-

7
4

检验:把x=-

7
4
代入x2-8x+7≠0,

∴原方程的解为x=-

7
4

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