Question

若

x-3

x2-1

=

A

x+1

-

B

x-1

，求A，B的值．

Answer 1

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

．