1.3a(a-b)+b(b-a) ＝3a(a-b)－b(a-b)＝﹙a－b﹚﹙3a－b﹚2.6(x-y)的立方-3y(y-x)²＝6﹙x－y﹚³－3y﹙x－y﹚²＝3﹙x－y﹚²﹙2－y﹚3.x(x-y)(a-b)-y(y-x)(b-a)＝x(x-y)(a-b)-y(x-y)(a-b)＝(x-y)(a...