8（x-y）平方（x+y）-6（y-x）三次方
问题描述：
8（x-y）平方（x+y）-6（y-x）三次方
答
8(x-y)²(x+y)-6(y-x)³
=8(x-y)²(x+y)+6(x-y)³
=2(x-y)²[4(x+y)+3(x-y)]
=2(x-y)²(4x+4y+3x-3y)
=2(x-y)²(7x+y)