## anonymous 5 years ago Help!! Im a little stuck.. I need to decompose this into partial fractions:

1. anonymous

$(2x^2-11x+5)/(x-3)(x^2+x-4)$

2. Hero

What course are you currently taking?

3. anonymous

This is Pre-Calc Hero

4. Hero

Okay, just wondering.

5. anonymous

Then I use A/(x-3)+B(x^2+x-4)

6. Hero

What textbook are you using for the course?

7. anonymous

Precalculus: Graphs and Models by Addison Wesley

8. Hero

Thanks

9. anonymous

Its pretty old. 1997

10. Hero

That's okay. Sometimes, old is better.

11. anonymous

Okay. I mean its probably all the same techniques, for the most part.

12. Hero

What edition?

13. Hero

Well, nevermind. I'll get get the latest edition.

14. anonymous

Ok I wasnt sure. I dont know if it says it for sure.

15. Hero

If you have the book, it will say what edition it is. You just have to look, but okay.

16. Hero

17. anonymous

I really dont see it at all :O This is the exact book though http://www.abebooks.com/book-search/isbn/0201694425/hard-cover/

18. anonymous

Ok thats fine. Thanks

19. Hero

If you want to show someone a book, use amazon.com

20. anonymous

ahh alright.

21. Hero

Yes, that version is very old. It's not even available for download. It's the first edition apparently

22. Hero

4 minutes left..

23. anonymous

ok

24. Hero

If you have the book, is there any reason why you are not able to understand this concept?

25. anonymous

I get the concepts down sort of, I just end up with the wrong numbers. I either do a step too early or Im not doing it completely right. I just want to make sure I understand it

26. Hero

Okay, I will have a look here in about 15 secs

27. anonymous

Ok Ill go through with what Im doing and you can maybe see what Im doing wrong

28. anonymous

Let me know when its done

29. Hero

It might take me a bit to figure this out.

30. anonymous

Ok thats fine!

31. Hero

Okay, I see something similar to this where it talks about setting up a decomposition template.

32. anonymous

Its in a lesson called Partial Fractions in my book

33. anonymous

That sounds right though

34. Hero

$\frac{2x^2 - 11x+5}{(x-3)(x^2+x-4)} = \frac{A}{x-3} + \frac{Bx + C}{x^2 + x -4}$

35. Hero

Maybe that's what you're looking for.

36. anonymous

So then its $A(x^2+x-4)+(x-3)(Bx+C)=2x^2-11x+5$

37. Hero

What I posted is in your book so it is correct. If what you posted is the next step, then by all means, go right ahead, but maybe someone else can take a look at that for you.

38. anonymous

Ok thats cool. I needed that for sure so thanks a lot Hero