Factories:
25 – a2 – b2 – 2ab
Given,
25 – a2 – b2 – 2ab
= 25 – (a2 + b2 + 2ab)
By using the formula a2 – b2 = (a + b)(a – b)
We get,
25 – a2 – b2 – 2ab = 25 – (a2 + b2 + 2ab)
= 25 – (a + b)2
=(5)2 – (a + b)2
= {5 + (a + b)}{5 – (a + b)}
= (5 + a + b)(5 – a – b)