Đáp án:
$\begin{array}{l}
\frac{{28.37 + 14.86}}{{7.40}}\\
= \frac{{14.2.37 + 14.86}}{{7.40}}\\
= \frac{{14\left( {2.37 + 86} \right)}}{{7.40}}\\
= \frac{{14.\left( {74 + 86} \right)}}{{7.2.20}}\\
= \frac{{14.160}}{{14.20}}\\
= \frac{{160}}{{20}} = 8
\end{array}$