问题 填空题

因式分-x2+2xy+y2=______.

答案

∵-x2+2xy+y2

=-(x2-2xy-y2

=-(x2-y2-2xy)

=-[(x-y)2-(

2
y)2]

=-(x-y+

2
y)(x-y-
2
y).

故答案为:-(x-y+

2
y)(x-y-
2
y).

单项选择题
单项选择题