tính 84 – 67

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{84}\\{67}\end{array}} \\\,\,\,\,17\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{15}\\{38}\end{array}} \\\,\,\,\,53\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{85}\\{57}\end{array}} \\\,\,\,\,28\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{67}\\{17}\end{array}} \\\,\,\,\,84\end{array}\)