Question

Factorise the following:

25 – a² + 2ab – b²

Answer 1

Given: 25 – a² + 2ab – b²

⇒ 5² – (a² – 2ab + b²)

⇒ 5² – (a – b)²

We know that,

(a + b) (a – b) = a² – b²

Hence,

⇒ (5 – a + b) (5 + a – b)