Question

3,4<2x+1<5,6 in multimea N

Answer 1

$3,4\ \textless \ 2x+1\ \textless \ 5,6~~~~~~~~~~~~~|-1 \\ 2,4\ \textless \ 2x\ \textless \ 4,6~~~~~~~~~~~~~~~~~~|:2 \\ 1,2\ \textless \ x\ \textless \ 2,3,~dar~x \in N \Rightarrow \boxed{x=2}.$