1/3a^2x^4-3b^2y^4

问题描述:

1/3a^2x^4-3b^2y^4

1/3a^2x^4-3b^2y^4
=1/3(a^2x^4-9b^2y^4)
=1/3(ax²+3by²)(ax²-3by²)