209 × 4
Giải thích
Lời giải\[\begin{array}{l} \times \begin{array}{*{20}{c}}\begin{array}{l}209\\{\rm{ }}4\end{array}\hline\end{array}\\{\rm{ }}836\end{array}\]
Lời giải\[\begin{array}{l} \times \begin{array}{*{20}{c}}\begin{array}{l}209\\{\rm{ }}4\end{array}\hline\end{array}\\{\rm{ }}836\end{array}\]