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mod help watch

    • Thread Starter

    hey i'm a little stuck on this question, I can seem to do it fine when actual values are being used but can't quite get an answer/know what I'm meant to be writing down as an answer for this question:

    Set h = gcd(a,n)
    If h does not divide b, then prove that ax = b(mod n) has no
    integer solutions for x.

    All i've managed to do is write h in terms of a and n using other parameters and saying there should be h solutions to it if there were any..not even sure if this is right?! Help!
    • Wiki Support Team

    Wiki Support Team
    Ok. Messy, but:

    We know that ax = np + b (*) for some integer p (why?). Now, let qh = a, rh = n, where q and r are integers (why can we do this?). Then we can rewrite (*) as...
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Updated: January 28, 2009

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