Proving ab|c: The Proof for (a,b)=1

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  • Thread starter Thread starter chaotixmonjuish
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Discussion Overview

The discussion revolves around proving that if \( a|c \) and \( b|c \) with \( (a,b)=1 \), then \( ab|c \). Participants explore the reasoning behind this proposition and share their thoughts on the proof provided by one member.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant presents a proof based on the property that \( (a,b)=1 \) implies \( au+bv=1 \), incorporating \( c \) into the equation.
  • Another participant affirms the correctness of the proof, indicating agreement with the reasoning presented.
  • There is a mention of the proposition being linked to the GCD, with one participant expressing a desire for more detailed explanations in textbooks.
  • Participants discuss the background of the individual who proposed the proof, noting their self-study approach in abstract algebra.

Areas of Agreement / Disagreement

There is agreement on the validity of the proof presented, but the discussion also reflects a shared sentiment about the need for more comprehensive explanations in educational materials.

Contextual Notes

Participants do not delve into the specific assumptions or definitions that underlie the proof, nor do they address any potential limitations in the reasoning provided.

Who May Find This Useful

This discussion may be of interest to students studying abstract algebra, educators looking for insights into common student challenges, and anyone interested in the properties of divisibility and GCD in number theory.

chaotixmonjuish
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If a|c and b|c with (a,b)=1, prove ab|c

The book just states that ab|c if (a,b)=1...so I took a stab on proving it:

(a,b)=1 means au+bv=1

so for no reason at all I threw in a c

acu+bcv=c

since a|c and b|c c=ak and c= bh

abhu+bakv=c

this means ab(hu+kv)=c

hence ab|c
It this proof right...the book kind of skips proving this proposition.
 
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Yes that's RIGHT!
 
Great! The book simply told me that the proposition is possible only because of the GCD...and the lack of a proof bothered me.
 
I agree with you, books should be more detailed!
By the way "congratulations!" since you proved very good in finding the proof by yourself!
Are you studing Algebra alone by yourself? Or are you attending university?
 
I'm actually taking an Intro to Abstract type course and I'm just aggressively nuturing my curiosity by borrowing abstract algebra books from the library and working stuff out.
 

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