Question

9 (a_ 2 )square - 16 (A + 2 ) square​

Answer 1

9(a-2)² - 16(a+2)²

= {3(a-2)}² - {4(a+2)}²

using x² - y²= (x+y)(x-y)

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

= (7a + 2)(-a -14)

= - (7a + 2) (a + 14)

= - (7a² + 100a + 28)