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Math Help - solving for x, exponential

  1. #1
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    solving for x, exponential

    5^x - 5^(3-x) = 20

    solving for x. not sure how to go about this
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  2. #2
    Master Of Puppets
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    I'll kick this off for you,

     5^x - 5^{3-x} = 20

     5^x - \frac{5^3}{5^x} = 20

    Now mulitply both sides through by 5^x we get

     5^{2x} - 5^3 = 20\times 5^x

    Making a = 5^x then

     a^2 - 5^3 = 20a

    Can you solve this quadratic?
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  3. #3
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    thanks, i abandoned this method after unknowingly making a sign error. i'm getting the desired answer now
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