问题 解答题
x-3
x2-1
=
A
x+1
-
B
x-1
,求A,B的值.
答案

A
x+1
-
B
x-1

=

A(x-1)-B(x+1)
(x+1)(x-1)

=

(A-B)x-(A+B)
x2-1

=

x-3
x2-1

A-B=1
A+B=3

解得:

A=2
B=1

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