Question

E URGENT!!! 100 DE PUNCTEEE!

Answer 1

$\it 7\in\{2n+1,\ 3n-8\} \Rightarrow \begin{cases} \it 2n+1=7|_{-1} \Rightarrow 2n=6|_{:2} \Rightarrow n=3\\ \\ sau\\ \\ \it 3n-8=7|_{+8} \Rightarrow 3n=15|_{:3} \Rightarrow n=5 \end{cases}$