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Math Help - Can someone help me with this question

  1. #1
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    Can someone help me with this question

    Determine which expression is the correct rationalization of the denominator of

    I would assume it is -5 but the answer is suppose to be B


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    The Question Is Here ^^
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  2. #2
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    Re: Can someone help me witht his question

    Just multiply numerator and denominator by \sqrt{5} + \sqrt{10}.
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  3. #3
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    Re: Can someone help me with this question

    hint ...

    \sqrt{5} \pm \sqrt{10} = \sqrt{5}(1 \pm \sqrt{2})
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  4. #4
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    Re: Can someone help me with this question

    Quote Originally Posted by waleedrabbani View Post
    Determine which expression is the correct rationalization of the denominator of

    I would assume it is -5 but the answer is suppose to be B


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    The Question Is Here ^^
    The denominator becomes -5, but you are not asked what does the denominator become. You are asked to give an expression that is EQUIVALENT to the expression which has been given, which has a rational denominator (and of course is fully simplified).
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  5. #5
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    Re: Can someone help me with this question

    I agree it is a weird question but I don't see how adding information would make it any less weird!
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  6. #6
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    Re: Can someone help me with this question

    Quote Originally Posted by HallsofIvy View Post
    I agree it is a weird question but I don't see how adding information would make it any less weird!
    I don't see what's so weird about it. The question asks the reader to write \displaystyle \begin{align*} \frac{\sqrt{5} + \sqrt{10}}{\sqrt{5} - \sqrt{10}} \end{align*} with a rational denominator. The OP has misinterpreted the question as asking what would the denominator becomes in the process of rationalising.
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