Question

Factorise the following:

a² – 16 + ab + 4b

Answer 1

Given: a² – 16 + ab + 4b

We know that,

(a + b)(a – b) = a² – b²

Hence,

⇒ a² – 4² + b(a + 4)

⇒ (a + 4)(a – 4) + b(a + 4) 

⇒ (a + 4)(a + b – 4)