Proving the GCD Property: A Challenge for Algebra Students

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urgent algebra GCD Proof problem

Homework Statement


let d=gcd(m,n). Prove that d=am+bn, where a,b are integers.


Homework Equations


use of induction and euclidean algorithm.


The Attempt at a Solution


i know when d being a generator and d=am+bn where m,n are generators, then d=gcd(m,n).
But i got stuck when proving the converse(which is the problem statement above).

I use the iterative algorithm(i.e. "n=qm+r";gcd(m,n)=gcd(m,r) and so on) but just does not work. And i do not know how to use "induction" in this proof.

Thank you for helping me.
 
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Use the Euclidean algorithm.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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