Question

Determinati numerele naturale n pentru care (n+2) | 91

Answer 1

Am atasat o fotografie

Answer 2

$(n+2) | 91 \Rightarrow \left\| \begin{array}{c} (n+2) \in D_{91} \\ dar \\ n\in \mathbb_{N}\Rightarrow (n+2)\in \mathbb_{N} \end{array} \right |\Rightarrow (n+2)\in D_{91}^+ \Rightarrow \\ \\ \\\Rightarrow (n+2)\in \Big\{1;91\Big\} \Big|-2 \Rightarrow n \in \Big\{-1;89\Big\}, dar, n\in \mathbb_{N} \Rightarrow \\ \\ \Rightarrow \boxed{n \in \Big\{89\Big\}}$