Question

Factarise 4a 2 -9b 2 -2a-3b

Answer 1

4a 2-9b 2-2a-3b

apply a2-b2 =(a+b)(a-b)

(2a)2-(3b)2-2a-3b

(2a+3b)(2a-3b)-2a-3b

(2a+3b)(2a-3b) -1(2a+3b)

now take 2a+3b as common in both brackets

(2a+3b)[2a-3b-1]