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Math Help - Divide radical expression

  1. #1
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    Divide radical expression

    6 / (3 + √5) = (18 - 6√5) / 4

    my question is that can u subtract 6 from 18..why or why not?
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  2. #2
    MHF Contributor Mathstud28's Avatar
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    Quote Originally Posted by Power View Post
    6 / (3 + √5) = (18 - 6√5) / 4

    my question is that can u subtract 6 from 18..why or why not?
    \frac{6}{3+\sqrt{5}}=\frac{18-6\sqrt{5}}{4}

    Multiplying both sides gets you \frac{24}{3+\sqrt{5}}=18-6\sqrt{5}

    now if you are asking from here can you subtract the asnwer is no because the two numbers do not have a common denominator
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  3. #3
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    Quote Originally Posted by Power View Post
    6 / (3 + √5) = (18 - 6√5) / 4

    my question is that can u subtract 6 from 18..why or why not?

    No. This is kind of how I saw it...
    the radical is like a variable...
    and the 18 and 6 are not like terms..
    ...just a thought...
    But I know you cant
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