Question

How do you factor `9z^2 + 27z -az - 3a`?

Answer 1

We can factor this expression by making groups of 2 terms:

`(9z^2 + 27z) -(az + 3a)`

`9z` is common to both the terms in the first group, and `a` is common to both the terms in the second group

`= 9z(z+3) - a(z+3)`

`z+3` is common to both the terms now

`= color(green)((z+3)(9z-a)`