[tex]\displaystyle\\
38)~f(x):R \to R,~~f(x)=3x-1\\\\
b)~\text{Rezolvati ecuatia: } ~~5\cdot f(x+1)=2x+11.\\\\
\texttt{Rezolvare: }\\\\
5\cdot f(x+1)=2x+11.\\\\
5[3(x+1)-1]=2x+11\\\\
5[3x+3-1]=2x+11\\\\
15x+15-5=2x+11\\\\
15x-2x=11-15+5 \\\\
13x=1\\\\
\boxed{x = \frac{1}{13} }[/tex]
