tính 451 + 319

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{451}\\{319}\end{array}} \\\,\,\,\,770\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{442}\\{318}\end{array}} \\\,\,\,\,124\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{442}\\{\,\,\,38}\end{array}} \\\,\,\,\,480\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{880}\\{565}\end{array}} \\\,\,\,\,315\end{array}\)