Question

factorise : 9a (x-2y)4 - 12a (x - 2y)3

Answer 1

9a (x-2y)4 - 12a (x - 2y)3

= 3a (x - 2y)3 [3(x - 2y) - 4]

=3a(x - 2y)3 [3x -6y - 4]