Question

Valorile naturale nenule ale lui n pentru care 42 supra 2n + 1 € N sunt

Answer 1

[tex]\dfrac{42}{2n+1}\in \mathbb{N}\Leftrightarrow 2n+1\in D_{42}\\ ~~~~~~~~~~~~~~~~~~~~~2n+1\in \{1,2,3,6,7,14,21,42\}\\ ~~~~~~~~~~~~~~~~~~~~~2n\in\{0,1,2,5,6,13,20,41\}\\ ~~~~~~~~~~~~~~~~~~~~~n\in \left\{0,\dfrac{1}{2},1,\dfrac{5}{2},3,\dfrac{13}{2},10,\dfrac{14}{2}\right \}\\ \text{Dar cum n}\in \mathbb{N}\Rightarrow n\in \{0,1,3,10\}[/tex]