Question

9a^2-(a^2-4)^2 factories

Answer 1

Answer:

9a^2-(a^2-4)^2

=(3a)^2-(a^2-4)^2

={3a+(a^2-4)}{3a-(a^2-4)}

=(3a+a^2-4)(3a-a^2+4)

=(a^2+3a-4)(-a^2+3a+4)