tính 731 - 380

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{731}\\{380}\end{array}} \\\,\,\,\,351\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{128}\\{390}\end{array}} \\\,\,\,\,518\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{524}\\{\,\,\,18}\end{array}} \\\,\,\,\,506\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{636}\\{145}\end{array}} \\\,\,\,\,781\end{array}\)