Question

计算：

1

x-1

-

2

x2-1

=

 

．

Answer 1

分析：根据分式的运算法则，先将分式通分再化简．

解答：解：原式=

x+1

(x-1)(x+1)

-

2

(x-1)(x+1)

=

x+1-2

(x-1)(x+1)

=

x-1

(x-1)(x+1)

=

1

x+1

．

点评：本题考查了分式的加减运算．解决本题首先应通分，最后要注意将结果化为最简分式．