Question

determinati n divizibil N , astfel incat 2n + 1 sa fie divizori a lui 13

Answer 1

$n \in N ~~~ si ~~~ 13 ~\vdots~ (2n-1)$ 
 
  
[tex]D_{13}=\{1;~13\} \\ 2n+1 = 1 ~~\Longrightarrow~~2n=1-1 ~~\Longrightarrow~~ 2n=0 ~~\Longrightarrow~~ n_1=\boxed{0} \\ \\ 2n+1 = 13 ~~\Longrightarrow~~2n=13-1 ~~\Longrightarrow~~ 2n=12 ~~\Longrightarrow~~ n_2= \frac{12}{2}= \boxed{6} [/tex]