Help with Proof: GCD(a,bk) = GCD(a,k)

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SUMMARY

The discussion centers on the mathematical proof that if gcd(a, b) = 1, then gcd(a, bk) = gcd(a, k). Participants explore the implications of the greatest common divisor (gcd) and its properties, particularly focusing on the relationship between the prime factorization of the numbers involved. The conclusion drawn is that both gcd(a, bk) and gcd(a, k) must divide k, leading to the assertion that they can be equal under specific conditions, particularly when k shares no common factors with a other than 1.

PREREQUISITES
  • Understanding of the concept of greatest common divisor (gcd)
  • Familiarity with prime factorization
  • Basic knowledge of number theory
  • Experience with mathematical proofs
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  • Study the properties of gcd, particularly in relation to coprime numbers
  • Learn about prime factorization techniques and their applications in number theory
  • Explore mathematical proof strategies, especially in the context of gcd
  • Investigate the implications of gcd in modular arithmetic
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Students of mathematics, particularly those studying number theory, educators teaching gcd concepts, and anyone interested in mathematical proofs and their applications.

Hells_Kitchen
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Hi there can someone help me on this one:
If gcd(a,b)=1 then gcd(a,bk) = gcd(a,k)

I have arrived at the conclusion that gcd(a,bk) gcd(a,k) both divide k but from here I do not get anywhere.

I would like some hints on this please.
 
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Hi, I think it is sufficient to prove that gcd(a,bk) and gcd(a,b) divide each other.
 
Hells_Kitchen said:
Hi there can someone help me on this one:
If gcd(a,b)=1 then gcd(a,bk) = gcd(a,k)

I have arrived at the conclusion that gcd(a,bk) gcd(a,k) both divide k but from here I do not get anywhere.

I would like some hints on this please.
could be that they both equal 1, for instance if k = b but think of expressing both a and k in the form of a product of primes. Since the gcd(a,k) is the product of the prime factors that are common to a and k or 1 if there are no common factors other than 1, and gcd(a,b), which is the product of the prime factors that are common to b and a, is 1, does k*b add any other factors of a?
 
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