[tex]\displaystyle\bf\\3^a+4b=\overline{ab} \Leftrightarrow 3^a+4b=10a+b \Leftrightarrow 3^a+3b=10a,~dar~3^a=\mathcal{M}_3,~3b=\mathcal{M}_3,\\10a=\mathcal{M}_3 \Leftrightarrow a=\mathcal{M}_3,~dar~evident,~daca~a\geq 6,~nu~vom~avea~solutii~naturale.\\a=0,~nu~convine.\\a=3 \implies b=1.[/tex]
