\[\begin{array}{l}
A = \frac{{3737:43 - 4343:47}}{{2 + 4 + 6 + ... + 100}} = \frac{{101.37:43 - 101.43:37}}{{2 + 4 + 6 + ... + 100}}\\
Tinh:\,\,B = \,2 + 4 + 6 + .... + 100\\
So\,\,cac\,\,so\,\,hang:\,\,\,\,\frac{{100 - 2}}{2} + 1 = 50\,\,so.\\
\Rightarrow B = \left( {100 + 2} \right).50:2 = 2550.\\
\Rightarrow A = \frac{{101.37:43 - 101.43:37}}{{2550}}\\
= \frac{{101\left( {37:43 - 43:37} \right)}}{{2550}} = \frac{{101}}{{2550}}\left( {\frac{{37}}{{43}} - \frac{{43}}{{37}}} \right)\\
= \frac{{101}}{{2550}}\left( {\frac{{{{37}^2} - {{43}^2}}}{{43.37}}} \right) = \frac{{101}}{{2550}}.\frac{{ - 480}}{{1591}} = - \frac{{101.16}}{{85.1591}}.
\end{array}\]
