化简:x2−2xy+y2−1x−y−1=_.

问题描述:

化简:

x2−2xy+y2−1
x−y−1
=______.

原式=

(x−y)2−1
x−y−1
=
(x−y+1)(x−y−1)
x−y−1
=x-y+1.