(1/2x+y)(1/2x-y)(1/4x2-y2).

问题描述:

1
2
x+y)(
1
2
x-y)(
1
4
x2-y2).

原式=(

1
4
x2-y2)(
1
4
x2
-y2
=
1
16
x4-
1
2
x2y2+y4