Respuesta :

remember revese distributeive
ab+ac=a(b+c)
factor out
(a^2)(x+3)+(-4)(x+3)
undistribute (like rreverse distribute where (x+3)=a)

(a^2-4)(x+3)
we can stil factor a^2-4 into a^2-2^2=(a-2)(a+2)

(a-2)(a+2)(x+3)