Question

enumerati elementele multimii A={x| xE N si (x-5)|(x+6)}​

Answer 1

$\it A=\{x\in \mathbb{N} \bigg|\ x-5|x+6\}\\ \\ \\ \left.\begin{aligned} \it x-5|x+6\ \ \ \ \ \\ \\ Dar,\ \it x-5|x-5\ \end{aligned}\right\} \Rightarrow x-5 |(x+6)-(x-5) \Rightarrow x-5|x+6-x+5 \Rightarrow \\ \\ \\ x-5| 11 \Rightarrow x-5\in\{1,\ 11\}\bigg|_{+5} \Rightarrow x\in\{6,\ \ 16\} \Rightarrow A=\{6,\ \ 16\}$