试题与答案

(1)计算:(2aa-1-1a+1)•a2-1a(2)解分式方程:1x-3=2+

题型:解答题

题目:

(1)计算:(
2a
a-1
-
1
a+1
)•
a2-1
a

(2)解分式方程:
1
x-3
=2+
x
3-x

答案:

(1)解法一:原式=

2a
a--1
a2-1
a
-
a
a+1
a2-1
a

=

2a
a-1
(a+1)(a-1)
a
-
a
a+1
(a+1)(a-1)
a

=2•(a+1)-(a-1),

=2a+2-a+1,

=a+3;

解法二:原式=

2a(a+1)-a(a-1)
a2-1
a2-1
a

=

a2+3a
a2-1
a2-1
a

=

a2+3a
a

=a+3;

(2)方程两边乘以(x-3),

得:1=2(x-3)-x,

1=2x-6-x,

∴x=7,

检验:将x=7代入原方程,左边=

1
4
=右边,

∴x=7是原方程的根.

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