计算：1x+1-x+2x2-1•x2-2x+1x2+4x+4．

题型：解答题难度：一般来源：不详

计算：

1

x+1

-

x+2

x2-1

•

x2-2x+1

x2+4x+4

．

答案

原式=

1

x+1

-

x+2

(x+1)(x-1)

•

(x-1)2

(x+2)2

=

1

x+1

-

x-1

(x+1)(x+2)

=

x+2-x+1

(x+1)(x+2)

=

3

(x+1)(x+2)

．