问题 填空题
计算:
x
(x-y)3
+
y
(y-x)3
=______.
答案

原式=

x
(x-y)3
-
y
(x-y)3
=
x-y
(x-y)3
=
1
(x-y)2

故答案为:

1
(x-y)2

解答题
判断题