tính 45 – 19

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{45}\\{19}\end{array}} \\\,\,\,\,26\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{78}\\{15}\end{array}} \\\,\,\,\,93\end{array}\)

\(\begin{array}{l}\underline { - \begin{array}{*{20}{c}}{86}\\{46}\end{array}} \\\,\,\,\,40\end{array}\)

\(\begin{array}{l}\underline { + \begin{array}{*{20}{c}}{26}\\{35}\end{array}} \\\,\,\,\,61\end{array}\)