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Math Help - Indices Question.

  1. #1
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    Indices Question.

    Aight, so the question is to "Solve the following equation".
    Unfortunately, I have no clue where to start...

    The equation is

    2^x + 2^{2x+3} =72

    Thanks in advance.
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  2. #2
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    Quote Originally Posted by ns2583 View Post
    Aight, so the question is to "Solve the following equation".
    Unfortunately, I have no clue where to start...

    The equation is

    2^x + 2^{2x+3} =72

    Thanks in advance.
    Note that

    2^{2x+3} = 2^3 \cdot 2^{2x} = 8 \cdot \left( 2^{x} \right)^2.
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  3. #3
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    Quote Originally Posted by danny arrigo View Post
    Note that

    2^{2x+3} = 2^3 \cdot 2^{2x} = 8 \cdot \left( 2^{x} \right)^2.
    I still don't know what goes next?
    Sorry.
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  4. #4
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    Quote Originally Posted by ns2583 View Post
    I still don't know what goes next?
    Sorry.
    So

    2^x + 8 \cdot \left( 2^{x} \right)^2 = 72,

    If we let y = 2^x we get a quadratic equation for y.
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