\[\begin{array}{l}
\overline {433ab} \,\,\,\,chia\,\,\,het\,\,\,cho\,\,\,2\,\,va\,\,\,5\\
\Rightarrow b = 0.\\
\Rightarrow So\,\,can\,\,tim\,\,\,co\,\,dang:\,\,\,\overline {433a0} .\\
Ta\,\,\,co:\,\,\,4 + 3 + 3 + a + 0 = 10 + a.\\
\Rightarrow \overline {433a0} \,\,\,\,chia\,\,\,het\,\,\,cho\,\,9\\
\Rightarrow 10 + a = 18\\
\Leftrightarrow a = 8.\\
\Rightarrow So\,\,\,can\,\,\,tim:\,\,\,43380.
\end{array}\]
