6a﹙a-b﹚²-12﹙b-a﹚²
问题描述：
6a﹙a-b﹚²-12﹙b-a﹚²
答
6a﹙a-b﹚²-12﹙b-a﹚²
=6a﹙a-b﹚²-12﹙a-b﹚²
=(6a-12)﹙a-b﹚²
=6(a-2)﹙a-b﹚²