3ax的4次方减3ay的4次方.
问题描述：
3ax的4次方减3ay的4次方.
答
3ax^4-3ay^4
=3a(x^4-y^4)
=3a(x^2+y^2)(x^2-y^2)
=3a(x^2+y^2)(x+y)(x-y)