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Math Help - Solving an exponential equation.

  1. #1
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    Solving an exponential equation.

    [(2x^1^/^3)-(5^1^/^3)]^3 = 35

    find X ???
    Last edited by mr fantastic; January 16th 2012 at 02:37 PM. Reason: Re-titled.
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  2. #2
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    Re: i want help with finding solution set of exponential equation

    Quote Originally Posted by mido22 View Post
    [(2x^1^/^3)-(5^1^/^3)]^3  =  35

    find X ???
    You can treat this like a normal equation to isolate 2x^(1/3):
    2x^{1/3} = \sqrt[3]{35} + 5^{1/3}
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  3. #3
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    Re: i want help with finding solution set of exponential equation

    sorry but this is not the right solution in my book....
    here is the main problem :
    (2x^1^/^3 - 5^1^/^3) (4x^2^/^3 + 2(5x)^1^/^3 + 25^1^/^3) = 35

    then i tried to simplify it as i wrote in the 1st post


    the solution set is {5}
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    Re: i want help with finding solution set of exponential equation

    Quote Originally Posted by mido22 View Post
    sorry but this is not the right solution in my book....
    Always state the problem in full, we can only answer what's put in front of us

    here is the main problem :
    (2x^1^/^3 - 5^1^/^3) (4x^2^/^3 + 2(5x)^1^/^3 + 25^1^/^3) = 35

    then i tried to simplify it as i wrote in the 1st post


    the solution set is {5}
    Start by expanding the brackets:

    Multiplying 2x^{1/3} by each term in the second bracket:

    8x + 4\sqrt[3]{5}x^{2/3} + 2\sqrt[3]{25}x^{1/3}


    Multiplying -5^{1/3} by each term in the second bracket

    -4\sqrt[3]{5}x^{2/3} - 2\sqrt[3]{25}x^{1/3} - 5

    The expanded form is the sum of these:

    \left(8x + 4\sqrt[3]{5}x^{2/3} + 2\sqrt[3]{25}x^{1/3}\right)

    + \left(-4\sqrt[3]{5}x^{2/3} - 2\sqrt[3]{25}x^{1/3} - 5\right) = 35


    Can you go from there? I expect a few terms will cancel
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  5. #5
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    Re: i want help with finding solution set of exponential equation

    Quote Originally Posted by e^(i*pi) View Post
    Always state the problem in full, we can only answer what's put in front of us



    Start by expanding the brackets:

    Multiplying 2x^{1/3} by each term in the second bracket:

    8x + 4\sqrt[3]{5}x^{2/3} + 2\sqrt[3]{25}x^{1/3}


    Multiplying -5^{1/3} by each term in the second bracket

    -4\sqrt[3]{5}x^{2/3} - 2\sqrt[3]{25}x^{1/3} - 5

    The expanded form is the sum of these:

    \left(8x + 4\sqrt[3]{5}x^{2/3} + 2\sqrt[3]{25}x^{1/3}\right)

    + \left(-4\sqrt[3]{5}x^{2/3} - 2\sqrt[3]{25}x^{1/3} - 5\right) = 35


    Can you go from there? I expect a few terms will cancel
    thank you vm! ....................................
    Last edited by mido22; January 16th 2012 at 01:06 AM.
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