(3m+3n)^2乘(2m-3n)^2过程
问题描述：
(3m+3n)^2乘(2m-3n)^2过程
答
是不是(2m+3n)^2(2m-3n)^2
=[(2m+3n)(2m-3n)]^2
=(4m^2-9n^2)^2
=16m^2-72m^2n^2+81n^2