Question

计算：

2

x+1

-

x-2

x2-1

÷

x2-2x

x2-2x+1

．

Answer 1

原式=

2

x+1

-

x-2

(x+1)(x-1)

×

(x-1)2

x(x-2)

=

2

x+1

-

x-1

x(x+1)

=

2x-(x-1)

x(x+1)

=

1

x

．