（X-Y)五次幂X(X-Y)四次幂=-（?）三次幂
问题描述：
（X-Y)五次幂X(X-Y)四次幂=-（?）三次幂
答
(X-Y)九次=-(X-Y)六次
1 X-Y=0
2 X-Y=-1
答
（X-Y)五次幂×(X-Y)四次幂
=(X-Y)九次幂
=-(Y-X)九次幂
=-[(Y-X)三次幂]三次幂
所以括号里填(Y-X)三次幂