MHB Prime Versus Irreducible Numbers

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A natural number p greater than 1 is defined as irreducible if for any natural numbers a and b, p dividing the product ab implies that p divides either a or b. The discussion centers on proving that if p is irreducible, then the equation p = ab leads to either p = a or p = b. The proof involves demonstrating that if p divides a or b, it must equal one of them due to their positive nature. This establishes that irreducible numbers greater than 1 are indeed prime. The conversation highlights the connection between irreducibility and primality in natural numbers.
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I don't quite know where to start with this one:

"A natural number p>1 is called irreducible if it has the property that, for any natural numbers a and b, p|ab always implies that either p|a or p|b (or both).

Prove that if a natural number p>1 is irreducible, then it also has the property that p=ab always implies that either p=a or p=b."

I figured that I essentially need to prove that irreducible natural numbers greater than 1 are prime.

Any help with this would greatly appreciated especially since I'm rather new to this site.
 
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Hi Panda,

Let $p$ be irreducible; let $a, b$ be natural numbers such that $p = ab$. Then $p | ab$, which implies $p | a$ or $p | b$ by irreducibility of $p$. If $p | a$, then since $a | ab = p$ we have $p = \pm a$. Since $p$ and $a$ are positive, $p = a$. Similarly if $p | b$, then since $b | p$ we deduce $p = b$.
 
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