[tex]\bold{2.}~(2x+3)~|~6 \Rightarrow 2x+3 \in D_{6}= \{ \pm1; \pm2; \pm 3; \pm6 \}. \\ \\ 2x+3=impar. \\ \\ 2x+3=-3 \Rightarrow x=-3. \\ 2x+3=-1 \Rightarrow x=-2. \\ 2x+3=1 \Rightarrow x=-1. \\ 2x+3=3 \Rightarrow x=0. \\ \\ \underline{Solutie}: x \in \{-3;-2;-1;0 \}.[/tex]
[tex]\bold{3.}~Suplementul~unghiului~cu~masura~135 \textdegree ~este~180 \textdegree-135 \textdegree=45 \textdegree. \\ Complementul~unghiului~cu~masura~45 \textdegree ~este~90 \textdegree - 45 \textdegree = 45 \textdegree. \\ \\ Raspuns:~45 \textdegree.[/tex]
[tex]\bold{4.}~\Rightarrow~2+a+3+5=a+10~-divizibil~cu~3. \\ a=cifra~\Rightarrow a \in \{2;5;8\}.[/tex]
[tex]\bold{5.}~180 \textdegree.[/tex]
