Factories:
(2x + 5y)2 – 1
Given,
(2x + 5y)2 – (1)2
= (2x + 5y)2 – (1)2
By using the formula a2 – b2 = (a + b)(a – b)
We get,
(2x + 5y)2 – (1)2 = (2x + 5y)2 – (1)2
= {(2x + 5y) + 1}{(2x + 5y) – 1}
= (2x + 5y + 1)(2x + 5y – 1)