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Homework Help: Partial fraction expansion (polynomial division)

  1. Mar 21, 2006 #1
    If we're asked to expand an irrational partial fraction, we need to rationalize it first, right? I've forgotten (well not totally) how to perform polynomial division. Here are a few examples:

    1. (1000x +1000000)/(.4x + 200).

    For this one I got 50000.

    2. (500x + 60000)/(x+100).

    For this one I got 600, is that right?

    It doesn't feel like I'm doing them correctly, if my answers are wrong can somebody walk me through them?
  2. jcsd
  3. Mar 22, 2006 #2
    This is fit enough even to be posted in a column even below the pre-calculus one.
    Just a zer is extra in 1st and you are wrong in 2nd. Don't post such silly things anymore.
  4. Mar 23, 2006 #3


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    Homework Helper

    Huh??? What??? What kind of help is THAT??? Are you threatening the OP not to post what he's not very sure about????
    Please note that, IF you do not feel like answering the OP's question, DO NOT bother to answer it. Let someone else do it for YOU!!!!!!!! :grumpy: :grumpy: :grumpy:
    seang, you may want to have a look at this page.
    I'll give you an example.
    [tex]\frac{2x + 5}{x + 3}[/tex]
    Now first, divide 2x by x to get 2. Then multiply the divisor (i.e x + 3) by the result you just obtained (i.e 2), you will get 2x + 6.
    Subtract (2x + 6) from (2x + 5) to get -1.
    -1 is of the degree 0, while x + 3 is of the degree 1, and 0 < 1. Hence, -1 is the remainder, and we can stop here.
    So the answer is:
    [tex]\frac{2x + 5}{x + 3} = 2 - \frac{1}{x + 3}[/tex]
    Can you go from here? :)
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