Results 1 to 3 of 3

Math Help - Help simplifiying expression

  1. #1
    Newbie
    Joined
    Aug 2009
    Posts
    3

    Help simplifiying expression

    Ok, so heres the problem, it asks me to simplify the expression:

    {(2x-1)^4 * 3(x+3)^2 - 4(2x-1)^3 * 2(x+3)^3} / (2x-1)^8


    I was thinking of using binomial therom since it looks like theres gonna be a lot of mulitplying


    heres what i tried:

    {(16x4+-32x3+24x2+-8x) * 3(1x2+6x1+9) - 4(8x3+-12x2+6x+-1) * 2(1x3+9x2+27x+27)} / (256x8+-1024x7+1792x6+-1792x5+1120x4+-448x3+112x2+-16x)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Dec 2007
    From
    Ottawa, Canada
    Posts
    3,069
    Thanks
    65
    {(2x-1)^4 * 3(x+3)^2 - 4(2x-1)^3 * 2(x+3)^3} / (2x-1)^8

    Easier if you start this way:
    a = 2x - 1, b = x + 3 ; then:
    (a^4 * 3b^2 - 4a^3 * 2b^3) / a^8

    a^3(a * 3b^2 - 4 * 2b^3) / a^8 ... get my drift?
    Then:
    (a * 3b^2 - 4 * 2b^3) / a^5
    (3ab^2 - 8b^3) / a^5
    b^2(3a - 8b) / a^5

    Now substitute back in.....

    By the way, I see no reason why your teacher wouldn't be impressed if you submitted:

    b^2(3a - 8b) / a^5 where a = 2x -1 and b = x + 3

    Depends on the teacher, I guess....
    Last edited by Wilmer; August 26th 2009 at 07:49 AM. Reason: none
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Aug 2009
    Posts
    3
    thanks alot dude! i thought it'd be much harder from looking at the big scary fraction
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 20
    Last Post: January 15th 2012, 09:30 AM
  2. Replies: 6
    Last Post: October 6th 2011, 01:48 PM
  3. Simplifiying help!
    Posted in the Algebra Forum
    Replies: 1
    Last Post: April 28th 2010, 09:49 PM
  4. Simplifiying - problem with parentheses
    Posted in the Algebra Forum
    Replies: 1
    Last Post: May 16th 2008, 09:34 PM
  5. Simplifiying a log expression
    Posted in the Algebra Forum
    Replies: 2
    Last Post: May 5th 2008, 08:26 PM

Search Tags


/mathhelpforum @mathhelpforum