Question

Factorise 9a^2-b^2 + 4b-4

Answer 1

Here is your answer.

Answer 2

9a^2-b^2+4b-4

=9a^2 -(b^2 - 4b + 4)

=9a^2- ((b)^2 - (2×b×2) + (2)^2)

=9a^2- (b-2)^2

=(9a-b+2) (9a +b-2)