[tex]\bold{Formula: \ M_a= \frac{x+y}{2} }; \\ x\to acest \ num\u{a}r;\\ Predecesorul \ lui \ x=x-1; \\ Succesorul \ lui \ x=x+1;\\ \frac{x+1+x-1}{2} =198 \\ \frac{2x+1-1}{2} =198 \\ \frac{2x}{2} =198 \\ 2x=198 \cdot 2 \\ 2x=396 \\ \Rightarrow x= \frac{396}{2} \\ \Rightarrow \boxed{x=198}.[/tex]
