Question

Factorise this 9 (a-2)^2-16(a+2)^2

Answer 1

9 (a-2)^2 -16 (a+2)^2

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

Now it is in the form of a^2 -b^2 which equals (a+b)(a-b)

={3 (a-2)+ 4 (a+2)}{3 (a-2)- 4 (a+2)}
=(3a -6 + 4a +8)(3a-6 -4a -8)
= (7a+2)(-a -14)

Answer 2

Hope it helps...........................