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    • Thread Starter
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    Hi,

    I can't work this out at all - can somebody help me please?




    Thanks in advance!
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    (Original post by ShivP_98)
    Hi,

    I can't work this out at all - can somebody help me please?




    Thanks in advance!
    Express each of the numbers under the root in prime factors first

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    (Original post by C0balt)
    Express each of the numbers under the root in prime factors first

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    Okay so

    sqrt(3 * 16) + sqrt(3 * 36)

    Like that?

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    squareroot = |

    |(48) + |(108)

    = |(3*16) + |(3*36)

    = 4|(3) + 6|(3)

    = 10|(3)
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    It needs to be in the form k sqrt6 though not 3
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    Also if anyone has any time;



    This one is hard for me too
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    • Very Important Poster
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    Very Important Poster
    Well, you know that \sqrt{a*b} is equal to \sqrt a * \sqrt b.

    You want each one in terms of \sqrt 6, so what do you do?

    Edit: Sorry, this was the more direct root route but I missed that other people were helping with a different method.
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    Try and make either a or b 6?
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    (Original post by ShivP_98)
    It needs to be in the form k sqrt6 though not 3


    Strange question but you have 10root3

    And 10 is 5 x root2 x root2
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    (Original post by ShivP_98)
    Also if anyone has any time;



    This one is hard for me too
    I assume that you can square what you have

    Then you need to adapt to make a^2 less than 10
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    (Original post by sophie_emma96)
    x = a X 10^n

    x^2 = (a X 10^n)^2

    x^2 = (a X 10^n)(a X 10^n)

    FOIL method:
    x^2 = a^2 + a10^n + a10^n + 100^2n

    x^2 = a^2 + 100^2n + 2(a X 10^n)
    This is incorrect ... Can suggest that you either correct it or delete it
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    (Original post by TenOfThem)
    This is incorrect ... Can suggest that you either correct it or delete it
    I don't know how to correct it so I will delete it haha! Could you share the correct answer as I'm intrigued now! 😂
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    (Original post by sophie_emma96)
    I don't know how to correct it so I will delete it haha! Could you share the correct answer as I'm intrigued now! 😂
    You squared a+b instead of ab

    (ab)^2 = a^2b^2
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    (Original post by TenOfThem)
    You squared a+b instead of ab

    (ab)^2 = a^2b^2
    Oops stupid error there, clearly need to get to bed
 
 
 
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