Factorise: 9a2+3a−8b−64b2
9a2+3a−8b−64b2=9a2−64b2+3a−8b=(3a)2−(8b)2+3a−8b=(3a−8b)(3a+8b)+1(3a−8b)=(3a−8b)(3a+8b+1)
Factorise:
9a2+19a2−2−12a+43a
Evaluate : (3a−12)(3a−12)