Question

化简求值：x2?2x+1x2?1÷x2?xx+1+1x?1，其中x=2

化简求值：x2?2x+1x2?1÷x2?xx+1+1x?1，其中x=2．

Answer 1

原式=

(x?1)2

(x?1)(x+1)

?

x+1

x(x?1)

+

1

x?1

=

1

x

+

1

x?1

=

x?1

x(x?1)

+

x

x(x?1)

=

2x?1

x(x?1)

=

2x?1

x2?x

，
将x=2代入上式得，原式=

2×2?1

22?2

=

3

2

．