Question

計(jì)算：

1

x2-1

+

x

1-x2

=

-

1

x+1

．

Answer 1

分析：先通分，再把分子相加減即可．

解答：解：原式=

1

(x+1)(x-1)

-

x

(x+1)(x-1)

=

1-x

(x+1)(x-1)

=-

1

x+1

．
故答案為：-

1

x+1

．

點(diǎn)評(píng)：本題考查的是分式的加減，熟知異分母分式的加減就轉(zhuǎn)化為同分母分式的加減是解答此題的關(guān)鍵．