Răspuns :
[tex]\it \hat2=2x+30 \ \ (corespondente)\\ \\ 4x+10=\hat2\ \ (opuse\ la\ v\hat arf)\\ \\ 4x+10=2x+30 \Rightarrow 4x-2x=30-10 \Rightarrow 2x=20|_{:2} \Rightarrow x=10^o[/tex]
[tex]\it \hat2=2x+30 \ \ (corespondente)\\ \\ 4x+10=\hat2\ \ (opuse\ la\ v\hat arf)\\ \\ 4x+10=2x+30 \Rightarrow 4x-2x=30-10 \Rightarrow 2x=20|_{:2} \Rightarrow x=10^o[/tex]