4a(2a-b)2-16a(a+2b)2.
问题描述:
4a(2a-b)2-16a(a+2b)2.
答
4a(2a-b)2-16a(a+2b)2
=4a[(4a2+b2-4ab)-4(a2+4b2+4ab)]
=4a(-15b2-20ab)
=-60ab2-80a2b.