Explicație pas cu pas:
[tex]\frac{13}{2x - 7}\in \mathbb{N} \implies (2x - 7) \in \mathcal{D}_{13} \\ \iff (2x - 7) \in \Big\{ 1; 13\Big\}[/tex]
[tex]2x - 7 = 1 \\ 2x = 1 + 7 \\ 2x = 8 \implies x = 4[/tex]
[tex]2x - 7 = 13 \\ 2x = 13 + 7 \\ 2x = 20 \implies x = 10[/tex]
[tex]\implies S = \Big\{ 4; 10\Big\}[/tex]
