tính 645 + 280

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{645}\\{280}\end{array}} \\\,\,\,\,925\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{658}\\{\,\,\,88}\end{array}} \\\,\,\,\,570\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{728}\\{167}\end{array}} \\\,\,\,\,561\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{262}\\{186}\end{array}} \\\,\,\,\,448\end{array}\)