[tex]\displaystyle\\
\frac{~~\overline{abab}~~}{\overline{baba}} = \frac{1000a+100b+10a+b}{1000b+100a+10b+a}= \frac{1010a+101b}{1010b+101a} = \\ \\ \\ =\frac{101(10a+b)}{101(10b+a)} = \texttt{ (Simplificam cu 101) } = \boxed{\frac{10a+b}{10b+a}} \\ \\ \\
\texttt{Raspuns: Fractia se simplifica cu: } ~~ \boxed{101}
[/tex]