计算(x²+2xy+y²)(x²-xy+y²)²
问题描述：
计算(x²+2xy+y²)(x²-xy+y²)²
答
=(x＋y)²(x－y)²
=[(x＋y)(x－y)]²
=(x²－y²)²
=x^4－2x²y²＋y^4