tính 76 – 47

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{76}\\{47}\end{array}} \\\,\,\,\,29\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{68}\\{23}\end{array}} \\\,\,\,\,91\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{85}\\{49}\end{array}} \\\,\,\,\,36\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{36}\\{47}\end{array}} \\\,\,\,\,83\end{array}\)