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    Prove that n² - 79n + 1601 is not always prime when n is a positive whole number
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    Proof by contradiction
    Got any ideas of numbers that might work (hint: the easiest one to spot is related to the numbers in the equation)
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    (Original post by Pastelx)
    Proof by contradiction
    Got any ideas of numbers that might work (hint: the easiest one to spot is related to the numbers in the equation)
    I'm not sure, I know that they are prime but what. umbers should I use in particular?
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    (Original post by Zain786H)
    I'm not sure, I know that they are prime but what. umbers should I use in particular?
    Okay, you know they are all prime and you have to find a number for n, which you can then square, multiply by something and then add a prime number to.

    The thing you have to make sure of is that your answer is a multiple of 1601 (multiplying and squaring means the number won't be prime, so you don't have to worry about that)

    Hence what value of n (the simplest value) is a multiple of 1601? –not a trick question!
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    (Original post by Pastelx)
    Okay, you know they are all prime and you have to find a number for n, which you can then square, multiply by something and then add a prime number to.

    The thing you have to make sure of is that your answer is a multiple of 1601 (multiplying and squaring means the number won't be prime, so you don't have to worry about that)

    Hence what value of n (the simplest value) is a multiple of 1601? –not a trick question!
    I understand now, thanks a lot, I subbed in 1601 as n so the product of the equation isn't prime and I believe 1523 and 1601 are the factors
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    (Original post by Zain786H)
    I understand now, thanks a lot, I subbed in 1601 as n so the product of the equation isn't prime and I believe 1523 and 1601 are the factors
    Good good! Np
 
 
 
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