Factorise:
9a2−4b2−6a+1
Given: 9a2−4b2−6a+1
=9a2−6a+1−4b2
={(3a)2−2(3a)+12}−(2b)2
=(3a−1)2−(2b)2 [∵(a2−2ab+b2=(a−b)2]
=(3a+2b−1)(3a−2b−1) [∵(a2−b2=(a+b)(a−b)]
9a2+19a2−2−12a+43a