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Math Help - Prime factorization question

  1. #1
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    Prime factorization question

    If 792 divides 13xy45z, find the digits, x y and z

    I know the prime factorization of 792, is 2^3*3^2*11. or 2^3*9*11.

    Around this time we were learning about quick ways to see if something can divide another, such as, 9 divides something if all the digits add up to a factor of 9.. Help anyone?
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  2. #2
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    Quote Originally Posted by MichaelG View Post
    If 792 divides 13xy45z, find the digits, x y and z

    I know the prime factorization of 792, is 2^3*3^2*11. or 2^3*9*11.

    Around this time we were learning about quick ways to see if something can divide another, such as, 9 divides something if all the digits add up to a factor of 9.. Help anyone?

    == An integer is an even one iff it ends in an even digit

    == An integer is divisible by 9 iff the sum of its digits is a multiple of 9

    == An integer is divisible by 11 iff [the sum of its digits in even position] minus [the sum of its digits in odd position] equals a multiple of 11.

    Now construct some equations and solve.

    Tonio
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