Factorize:
(a + b)3 – (a – b)3
We know that,
a3 - b3 = (a - b) (a2 + a × b + b2)
Using this formula, we get
= [a + b – (a – b)] [(a + b)2 + (a + b) (a – b) + (a – b)2]
= (a + b – a + b) [a2 + b2 + 2ab + a2 – b2 + a2 + b2 – 2ab]
= 2b (3a2 + b2)