(x-y)³(y-x)²(y-x)³=- (y-x)8 （8次方）
(x-y)³(y-x)²(y-x)³=(x-y)³(x-y)²[-(x-y)³]=-(x-y)³+³+²=(x-y)8
同意，慢慢算
慢慢算
