Factories:

16a2 – 144

We have,


16a2 – 144


= (4a)2 – (12)2


By using the formula a2 – b2 = (a + b)(a – b)


We get,


16a2 – 144 = (4a)2 – (12)2


= (4a + 12)(4a – 12)


= 4(a + 3) 4(a – 3)


= 16(a + 3)(a – 3)


7