\(\Rightarrow100a+10b+b+100a+10c+b=100c+10b+a\)
\(\Rightarrow200a+11b+11c=100c+10c+a\)
\(\Rightarrow199a+b=89c\Rightarrow199a=89c-b⋮199\left(1\right)\)
\(b\le9\Rightarrow89c-b\le810-9=801\left(2\right)\)
\(\left(1\right);\left(2\right)\Rightarrow\hept{\begin{cases}89c-b⋮199\\89b-c\le801\end{cases}}\)
Rồi lấy số chia hết 199 rồi xét vào là xong