Question

因式分解a的2次方（a-b）+b的2次方（b-a）=多少

Answer 1

a²﹙a－b﹚＋b²﹙b－a﹚
=a²﹙a－b﹚－b²﹙a－b﹚
=﹙a－b﹚²﹙a＋b﹚

Answer 2

a²﹙a－b﹚＋b²﹙b－a﹚
=a²﹙a－b﹚－b²﹙a-b)(=(a-b)(a²-b²)
=(a-b)(a+b)(a-b)
=﹙a－b﹚²﹙a＋b﹚