Question

So I have a question. How do I factor (2x^3 + 11x^2 - 20x -13)

Answer 1

Hi there! Are you completely lost or do you have some idea where to start?

Answer 2

I know some what where to start, the 13 is throwing me off a tad.

Answer 3

Hmm, I see exactly what you mean. When I read this I thought it was a 12 for some reason. However, I can still help you out. Let me try to scratch this out, okay?

Answer 4

Ya go for it!

Answer 5

Okay, so we know that your first term \[2x^3 \] can only be factored into \[2 * x* x\]
It's the same with your last term, 13.
13 can only be factored into \[13*1\]

Answer 6

Ya, so far I have (2x +- 13) (x +-1) ( x+- 1). But I wasn't sure if that was correct so far. Then I needed to find the correct sign for each factor.

Answer 7

Sorry, \[2x^3 \] can be factored into \[2 * x* x * \]So since these numbers are soooo AWKWARD, we have to find roots. Let's try (2x +1) and see if we can pull that out. Do you know how to do this?

Answer 8

Whoa! 0_o Didn't see that you had posted that, wow!

Answer 9

I'm not entirely sure of that order, I wanted to get a second opinion first before going into it so I didn't get to far off track.

Answer 10

I'm working this out. Give me 2 minutes, okay? :)

Answer 11

Ya no problem!

Answer 12

Wow; I'm really sorry about this. I'm not sure where to go from here; I'm tempted to say this isn't factorable. Let me see @Hero

Answer 13

No problem! Just a homework problem, I don't need to turn it in but I just wanted to do them to help study for finals.

Answer 14

If it helps at all, even though I'm know I am correct so far with the question. I need to final all real and complex zeros of f(x) = 2x^4 + x^3 - 35x^2 - 113x +65.

After I did synthetic division to get x = 5 to get a remainder of 0 then I get the original function to find the zeros/factors.

Answer 15

find* not final

Answer 16

This one looks right to me! I love synthetic division, it's way less time consuming.

However, I really think you should let the person I called help you. It would be helpful if you mentioned him in this thread, too. I messaged him, so he may be over here soon. @Hero

As to your other reply, Thanks; I just really like to make sure that I'm helping. This actually hasn't happened to me before! 0_0 I can usually help everyone so far. I guess today I met my match. *dark grin* XD

Answer 17

He's here! :D

Answer 18

Yes it is!

Okay cool thanks!

Answer 19

You're welcome. Sorry about that. :) @Hero do you know what to do?

Answer 20

Thanks! =D

Answer 21

I gave you the medal because you actually took steps to find your own answers. Many users don't do that; they just want the helper to do all of the work. You deserved a medal; you're welcome. :)

Answer 22

Ya, I was looking all over to see if there was someone else who had already done the problem to see where I could go from there but no such luck =/

Answer 23

What? I was right!!!!

Answer 24

Hmmmm... So how would I go about finding the zeros of equation without a graphing calculator?

Answer 25

Ya I have my textbook out now. Original was

f(x) = 2x^4 + x^3 - 35x^2 - 113x +65

After synthetic division using 5 and receiving a remainder of zero you get;

2x^3 + 11x^2 + 20x -13

Answer 26

I just realized that my original statement above said -20... But I still don't know how to go about it because all of my work has been for +20 anyways

Answer 27

Sorry...

Answer 28

I believe I have it now. Sorry to waste your time =(