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    Hey, not sure how to work out this question.

    a) Factorise 5x^2 + 6xy + y^2
    b) Hence, write 50601 as a product of two integers both of which are greater than 5.

    I can do a) easily. I get (x+y)(5x+y).

    But I'm not sure about b).

    Obviously it'll be (x+y)(5x+y) = 50601. But I don't know how to carry on from here :no:

    Thanks in advance
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    Write 5x^2 + 6xy + y^2 = 50601 and see what you can spot.
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    (Original post by yusufu)
    Write 5x^2 + 6xy + y^2 = 50601 and see what you can spot.
    Well it's a quadratic in terms of x (or y), so I suppose I could find x in terms of y or vice-versa. But that doesn't help, does it?
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    (Original post by gyyy2807)
    Well it's a quadratic in terms of x (or y), so I suppose I could find x in terms of y or vice-versa. But that doesn't help, does it?
    5x^2 + 6xy + y^2 = 50601 = 50000 + 600 + 1

    Does that help?
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    (Original post by yusufu)
    5x^2 + 6xy + y^2 = 50601 = 50000 + 600 + 1

    Does that help?
    ah ha I see now Thanks a lot
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    (Original post by yusufu)
    5x^2 + 6xy + y^2 = 50601 = 50000 + 600 + 1

    Does that help?
    that would mean that x = 100 and y = 1

    but the question says that both integers have to be greater than 5. so that wouldn't work.

    Edit: sorry, problem solved. Thanks again
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    (Original post by gyyy2807)
    that would mean that x = 100 and y = 1

    but the question says that both integers have to be greater than 5. so that wouldn't work.
    Are you allowed to use a calculator/know the prime compostition of 50601?
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    (Original post by JAKstriked)
    Are you allowed to use a calculator/know the prime compostition of 50601?
    not allowed calculator. No I don't know the prime composition of 50601.
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    (Original post by gyyy2807)
    not allowed calculator. No I don't know the prime composition of 50601.
    edit: Steve is right.

    I guess we're both guilty of not reading the question!
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    (Original post by gyyy2807)
    that would mean that x = 100 and y = 1

    but the question says that both integers have to be greater than 5. so that wouldn't work.
    x+y=100+1=101
    5y+x=501

    Both numbers are over 5
    (101)(501)=50601
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    (Original post by steve2005)
    x+y=100+1=101
    5y+x=501

    Both numbers are over 5
    holy ****. yeah. somehow I thought x and y had to be over 5.

    Thanks
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    (Original post by JAKstriked)
    edit: Steve is right.

    I guess we're both guilty of not reading the question!
    yeah. silly mistake to make. Thanks for trying anyway
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    very interesting question!!!!!
 
 
 
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