\(\overline{ab}\cdot5+18=\overline{bab}\)
\(\Rightarrow\overline{ab}\cdot5+18=b\cdot100+\overline{ab}\)
\(\Rightarrow\overline{ab}\cdot5-\overline{ab}+18=b\cdot100\)
\(\Rightarrow\overline{ab}\cdot4=b\cdot100-18\)
\(\Rightarrow\overline{ab}\cdot4:2=\left(b\cdot100-18\right):2\)
\(\overline{ab}\cdot2=b\cdot50-9\)
Ta có: \(\overline{ab}\cdot2\) ⋮ \(2\)
\(\Rightarrow b\cdot100-9\) ⋮ \(2\)
Mà: \(b\cdot100\) ⋮ 2 còn 9 ⋮ 2 (vô lý)
Vậy không có giá trị \(\overline{ab}\) phù hợp