计算:(y-x)的立方*(x-y)的n次方+2(x-y)的n+1次方*（y-x）的平方
问题描述：
计算:(y-x)的立方*(x-y)的n次方+2(x-y)的n+1次方*（y-x）的平方
答
解
(y-x)³(x-y)^n+2(x-y)^(n+1)(y-x)²
=-(x-y)³(x-y)^n+2(x-y)^(n+1)(x-y)²
=-(x-y)^(n+3)+2(x-y)^(n+3)
=(x-y)^(n+3)