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Homework Help: Help with a few problems

  1. May 11, 2004 #1
    i'm havin trouble with a few problems on my homework so help would be much appriciated

    solve for x:

    1) 3x^2 - 2x +1=0

    2) x^2 -4x + 20 = 0

    3) (-2/x+1) + (3/1-x) = 7/x^2-1

    and
    find p(-2) if P(x) = 2x^4 - x^3 + 4x^2 + -8x + 3

    again thx for any help :)
     
  2. jcsd
  3. May 11, 2004 #2

    enigma

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    Look up the quadratic formula for the first three.

    For the last one, substitute -2 in everywhere you see x, multiply and add them together.

    If you post an attempt, we can help you a bit more.
     
  4. May 11, 2004 #3
    i didnt think of using the quadratic formula i tried it but it still doesnt seem right i got
    x=2/3 + or - i root60/6 for the 1st 1

    and x = 6,-2 for the 2nd i must be doing something wrong
     
  5. May 11, 2004 #4

    enigma

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    I've got complex answers for both of the first two as well, but they don't match your results. Probably missed a '-' sign somewhere.

    For the third one, it looks like your parenthesis are a bit ambiguous.

    (-2/x+1)

    Is this (-2/x) +1 or -2/(x+1)?

    Can you post your work, and we'll find the errors?
     
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