How do you simplify y^2-9/3+9y? Thanks :)

Question

anonymous · Answer

What? How do you get -y?

anonymous · Answer

Yes. I want to understand it. I get a different answer...

anonymous · Answer

Is it supposed to be 3y+9?

anonymous · Answer

The original problem

anonymous · Answer

$$y^2-9=(y+3)(y-3)$$$$3y+9=3(y+3)$$
The y+3 will cancel out, so you get $$(y-3)/3$$

anonymous · Answer

but the problem says 3+9y.. :/

anonymous · Answer

Hmm...that's not going to simplify nicely.

anonymous · Answer

-y won't be correct

anonymous · Answer

Yeah its going to be hard. I dont know what to do..

anonymous · Answer

It can't be simplified in any meaningful way.  Are you sure the problem is written correctly?

anonymous · Answer

I got it in my college algebra book so it should be correct? Unless its one of those trick questions.

anonymous · Answer

Probably...jerks.  Is it supposed to be simplified by synthetic division?

anonymous · Answer

No. It just says simplify the following rational expressions. :/

anonymous · Answer

Ah, in that case, it's simplified already.

anonymous · Answer

But cant you simplify the denominator into 3(1+3y)??

anonymous · Answer

sure

anonymous · Answer

You can do that, but it's not really any simpler.

anonymous · Answer

what are you gonna do with that ?

anonymous · Answer

Oh ok. Well thank you!! :D

anonymous · Answer

Thats what I was thinking.. Is it?

anonymous · Answer

a-b looks good to me.

anonymous · Answer

You have to assume that a is larger than or equal to b