Question

use the identity (a + 3b) (a + 5b)​

Answer 1

Answer:

... For the above expression, keeping a=5a and b=3b, we get.

Answer 2

Answer:

Using Identity: (x + a)(x + b) = x² + (a + b)x + ab

(a+3b)(a+5b) = a² + (3b+5b)a +3b*5b

= a² + 8ab + 15b²