x2+2xy+y2x2y+xy2−x2−2xy+y2x2y−xy2.
问题描述:
−
x2+2xy+y2
x2y+xy2
.
x2−2xy+y2
x2y−xy2
答
原式=
-(x+y)2
xy(x+y)
,(x−y)2
xy(x−y)
=
-x+y xy
,x−y xy
=
,x+y−x+y xy
=
,2y xy
=
.2 x