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Math Help - Simplifying exponents

  1. #1
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    Simplifying exponents



    however i get a different calculation
    (27)^-1/3 = 9


    (27)^-1/3 = 9 * 2/9 = -2/3 then -2/3 * -27 = 54/3Q = 18/Q
    Last edited by mr fantastic; April 9th 2010 at 12:00 AM. Reason: Changed post title
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  2. #2
    Super Member Bacterius's Avatar
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    Hello,

    27^{\frac{-1}{3}} = \frac{1}{3} \neq 9

    It should work out fine now.
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  3. #3
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    Quote Originally Posted by Bacterius View Post
    Hello,

    27^{\frac{-1}{3}} = \frac{1}{3} \neq 9

    It should work out fine now.
    27^-1/3 is -1/3 then?

    2/9*-(1/3) = 2/27

    then -2/27 * 27/q = 54/27Q = 2/1q =2/q
    is that correct
    Last edited by matlondon; April 9th 2010 at 07:34 AM.
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  4. #4
    Super Member Bacterius's Avatar
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    Quote Originally Posted by matlondon View Post
    27^-1/3 is -1/3 then?

    2/9*-(1/3) = 2/27

    then -2/27 * 27/q = 54/27Q = 2/1q =2/q
    is that correct
    No. 27^(-1/3) = 1/3. Try without the minus sign.
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  5. #5
    Senior Member AllanCuz's Avatar
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    Quote Originally Posted by matlondon View Post
    27^-1/3 is -1/3 then?

    2/9*-(1/3) = 2/27

    then -2/27 * 27/q = 54/27Q = 2/1q =2/q
    is that correct
    Note that
    27=3^3
    so <br />
 27^-1/3 = (3^3)^-1/3
    where the exponents cancel and we are left with 1/3. There is no negative, the negative exponent simply indicates that we have 1 over the value.
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