(4a+2b-3c)(2b-4a+3c)
问题描述：
(4a+2b-3c)(2b-4a+3c)
答
提示：用平方差公式.
(4a+2b-3c)(2b-4a+3c)
=[2b+(4a-3c)][2b-(4a-3c)]
=(2b)²-(4a-3c)²
=4b²-(16a²-24ac+9c²)
=-16a²+4b²-9c²+24ac