因式分解:4(a-3)^2-(a+3)^2

问题描述:

因式分解:4(a-3)^2-(a+3)^2

4(a-3)^2-(a+3)^2 =[2(a-3)]^2-(a+3)^2 =[2(a-3)+(a+3)][2(a-3)-(a+3)] =(3a-3)(a-9) =3(a-1)(a-9)