1、a³－ab²=a(a²－b²)=a(a－b)(a＋b)2、ab²－2ab＋a=a(b²－2b＋1)=a(b－1)²3、ax²＋6ax＋9a=a(x²＋6x＋9)=a(x＋3)²4、x^4－y^4=(x²－y²)(x²＋y²)=(x－y)(x＋y)(x²＋y²)
a(a+b)(a-b)a(b-1)^2a(x+3)^2(x^2+y^2)(x+y)(x-y)
