Question

Factor by Grouping:

4z² + 12z - az - 3a

Answer 1

In factoring by grouping, you factor the first two terms and then the last two.

Answer 2

So then the first two terms would come out to 4z(z + 3) ?

Answer 3

Yes, and the last two?

Answer 4

-a(z + 3)

Answer 5

Okay, so you have \(4z(z + 3) - a(z + 3)\). Can you factor that further?

Answer 6

Nope, not that I can see. Unless I can do something with both (z+3)'s...

Answer 7

Yes, you can!

Answer 8

For example, you have \(ax + bx\). You may factor it so it becomes \((a + b)x\). The same way, you can always apply the trick to this one ;)

Answer 9

then in this case, I would replace x with (z + 3)?
(4z - a)(z + 3)?

Answer 10

Yes!

Answer 11

Much obliged!