tính 70 – 31

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{70}\\{31}\end{array}} \\\,\,\,\,39\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{26}\\{36}\end{array}} \\\,\,\,\,62\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{58}\\{13}\end{array}} \\\,\,\,\,45\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{52}\\{23}\end{array}} \\\,\,\,\,29\end{array}\)