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Homework Help: Simplifying this equation

  1. Sep 8, 2011 #1
    1. The problem statement, all variables and given/known data
    simplify:

    (x^(a-1))/x^((3a+4))



    2. Relevant equations

    i was really dumb to think laws of logarithms would help me, but obviously not...

    3. The attempt at a solution

    the only thing i know is that the a's cant cancel!! i dont know what to do !!!
     
  2. jcsd
  3. Sep 8, 2011 #2
    Think about the following:

    x^a/x^b=(x^a)(x^-b)

    Then,

    (x^a)(x^-b)=x^[(a)(-b)]

    In the problem you presented think FOIL.
     
  4. Sep 8, 2011 #3

    eumyang

    User Avatar
    Homework Helper

    Do you mean this?
    [tex]\frac{x^{a-1}}{x^{3a+4}}[/tex]
    BTW, I don't mean to nitpick, but this is not an equation. It is an expression. Please don't confuse the two.

    If that's an a times negative b at the end, then that is not correct. We need to use one of the properties of exponents, mainly this one:
    [tex]\frac{x^m}{x^n}=x^{m-n}[/tex]
     
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