Question

Mă ajutați ex 5 dau coroană

Answer 1

$\frac{3}{x + 1} \: \in \: \mathbb{N} = > x + 1 \: \: \vdots \: \: 3$

$=>x+1\:\in\:D_{3}$

$= > x + 1 \: \in \: \left \{ \pm1,\pm3 \right \}$

$x + 1 = - 1 = > x = - 2 \: \notin \: \mathbb{N}$

$x + 1 = 1 = > x = 0 \: \in \: \mathbb{N}$

$x + 1 = - 3 = > x = - 4 \: \notin \: \mathbb{N}$

$x + 1 = 3 = > x = 2 \: \in \: \mathbb{N}$

$S=\left \{ 0,2 \right \}$

$=>B)\left \{ 0,2 \right \}$