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Math Help - exponents

  1. #1
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    exponents

    Basicly, ive got the following:

    8^2.5 times 2^-0.5

    On the mark scheme, it changes the 8^2.5 to 2^7.5

    I don't understand how it does this step. Can anyone explain?
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  2. #2
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    Hello,

    Quote Originally Posted by nugiboy View Post
    Basicly, ive got the following:

    8^[2.5] * 2^[-0.5]

    On the mark scheme, it changes the 8^[2.5] to 2^[7.5]

    I don't understand how it does this step. Can anyone explain?

    8=2^3

    And you know that (a^b)^c=a^{bc}


    Plus, a^b a^c=a^{b+c}

    This is all you need for getting from one formula to another.
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  3. #3
    MHF Contributor
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    Quote Originally Posted by nugiboy View Post
    Basicly, ive got the following:

    8^[2.5] * 2^[-0.5]

    On the mark scheme, it changes the 8^[2.5] to 2^[7.5]

    I don't understand how it does this step. Can anyone explain?
    8^{2.5} = (2^3)^{2.5} = 2^{3\cdot{2.5}} = 2^{7.5}

    It's just rules of exponents.
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