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Maths

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    What is 51-14 sqrt 2 divided by 3 -2 sqrt 2
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    (Original post by Elisa2000)
    What is 51-14 sqrt 2 divided by 3 -2 sqrt 2
    It's a secret
    Spoiler:
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    multiply top and bottom by 3+2 sqrt 2
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    (Original post by EricPiphany)
    It's a secret
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    multiply top and bottom by 3+2 sqrt 2
    What did you get overall?
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    (Original post by Elisa2000)
    What did you get overall?
    I didn't. What did you get?
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    (Original post by EricPiphany)
    I didn't. What did you get?
    I got 41 -20 sqrt 2
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    (Original post by Elisa2000)
    I got 41 -20 sqrt 2
    Try again.
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    (Original post by RDKGames)
    Try again.
    Well, could you show me what the right answer is? Without using a calculator
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    (Original post by Elisa2000)
    Well, could you show me what the right answer is? Without using a calculator
    Show your working and I'll tell you where you went wrong.
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    (Original post by RDKGames)
    Show your working and I'll tell you where you went wrong.
    51 - 14 sqrt 2/ 3 -2 sqrt 2 both multiplied by 3+2 sqrt 2. Then I got 153 + 102 sqrt 2 - 42 sqrt 2 - 28 - 2 divided by 9-4-2 which gave me: 123-60 sqrt 2 /3. I divided it by three, which gave me 41 -20 sqrt 20
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    (Original post by Elisa2000)
    What is 51-14 sqrt 2 divided by 3 -2 sqrt 2
    \frac{51-14\sqrt{2}}{3-2\sqrt{2}}?
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    (Original post by XOR_)
    \frac{51-14\sqrt{2}}{3-2\sqrt{2}}?
    Could you help me with this?
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    (Original post by Elisa2000)
    51 - 14 sqrt 2/ 3 -2 sqrt 2 both multiplied by 3+2 sqrt 2. Then I got 153 + 102 sqrt 2 - 42 sqrt 2 - 28 - 2 divided by 9-4-2 which gave me: 123-60 sqrt 2 /3. I divided it by three, which gave me 41 -20 sqrt 20
    Well you simply multiplied wrong.

    Numerator: (51-14\sqrt{2})(3+2\sqrt{2})=51(3+2 \sqrt{2})-14\sqrt{2}(3+2\sqrt{2})

    =153+102 \sqrt{2}-42\sqrt{2}-28\sqrt{2} \sqrt{2}

    Denominator: (3-2\sqrt{2})(3+2\sqrt{2})=9-4\sqrt{2}\sqrt{2}

    Now simplify and carry on.
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    multiply top and botton by (3 + 2(sqrt2)) to rationalize the denominator

    EDIT: left for a few minutes and was answered i cri erry tim
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    (Original post by RDKGames)
    Well you simply multiplied wrong.

    Numerator: (51-14\sqrt{2})(3+2\sqrt{2})=51(3+2 \sqrt{2})-14\sqrt{2}(3+2\sqrt{2})

    =153+102 \sqrt{2}-42\sqrt{2}-28\sqrt{2} \sqrt{2}

    Denominator: (3-2\sqrt{2})(3+2\sqrt{2})=9-4\sqrt{2}\sqrt{2}

    Now simplify and carry on.
    isn't it 3-2sqrt(2)
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    (Original post by XOR_)
    isn't it 3-2sqrt(2)
    Huh? Where?
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    (Original post by RDKGames)
    Huh? Where?
    The original questions' denominator.
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    If you want my answer:
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    I got 97 - 60√2
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    (Original post by XOR_)
    The original questions' denominator.
    Yes it is. I'm showing multiplication by the conjugate of it.
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    (Original post by Notch)
    If you want my answer:
    Spoiler:
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    I got 97 - 60√2
    Close.
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    (Original post by RDKGames)
    Well you simply multiplied wrong.

    Numerator: (51-14\sqrt{2})(3+2\sqrt{2})=51(3+2 \sqrt{2})-14\sqrt{2}(3+2\sqrt{2})

    =153+102 \sqrt{2}-42\sqrt{2}-28\sqrt{2} \sqrt{2}

    Denominator: (3-2\sqrt{2})(3+2\sqrt{2})=9-4\sqrt{2}\sqrt{2}

    Now simplify and carry on.
    Look, minus sqrt 2 and sqrt 2 when multiplied make minus 2

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