1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Factoring Algebraic Expressions with Fractional Exponents

  1. May 21, 2009 #1
    1. The problem statement, all variables and given/known data

    [tex](4x-1)^{1/2}-1/3(4x-1)^{3/2}[/tex]


    2. Relevant equations



    3. The attempt at a solution

    I think the GCF is [tex](4x-1)^{1/2}[/tex]. So, I get [tex](4x-1)^{1/2}(1+(-1/3(4x-1)))[/tex] = [tex](4x-1)^{1/2}(-4/3x+4/3)[/tex] = [tex]-4/3(4x-1)^{1/2}(x-1)[/tex]

    However, the answer in the book is [tex]4/3(4x-1)^{1/2}(x-1)[/tex]. I've done it several ways, and I either get a minus sign on the [tex]4/3[/tex], or the [tex](x-1)[/tex] becomes [tex](x+1)[/tex].

    What am I missing?
     
  2. jcsd
  3. May 21, 2009 #2

    Cyosis

    User Avatar
    Homework Helper

    If the problem you've listed is the same as the problem in your book, then you're right and the answer in your book is wrong.
     
    Last edited: May 21, 2009
  4. May 21, 2009 #3

    berkeman

    User Avatar

    Staff: Mentor

    You can also check your work versus the book answer by plugging in a number for x, and solving the original expression and your final expression with a calculator. What answers do you get, for example, for x = 2?
     
  5. May 21, 2009 #4
    Thanks folks! I did try inputting a value for x, but I was still put off by the book's answer. I just wanted to verify from those more knowledgeable than I.

    Thanks!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Factoring Algebraic Expressions with Fractional Exponents
Loading...