[tex]\displaystyle \\
(3x + 1)~|~16 ~~~\\\
\texttt{Echivalent cu: } \\
16 ~\vdots ~(3x+1) \\
\texttt{Echivalent cu: } \\ \\
\frac{16}{(3x+1)} \in N \\ \\
\text{Rezolvare: }
D_{16} = \{ 1;~ 2; ~4;~ 8;~ 16\} \\ \\
3x+1 = 1 ~~\Longrightarrow ~~ x_1 = 0 \\ \\
3x+1 = 2 ~~\Longrightarrow ~~ x \notin N \\ \\
3x+1 = 4 ~~\Longrightarrow ~~ x_2 = 1 \\ \\
3x+1 = 8 ~~\Longrightarrow ~~ x \notin N\\ \\
3x+1 = 16 ~~\Longrightarrow ~~ x_3 = 5 [/tex]