Đáp án:
$\begin{array}{l}
1)B = \left\{ {72;144;216;288;360;432} \right\}\\
2)a)\left( { - 9989} \right) - \left( {2008 - 9989} \right) + \left( { - 192} \right)\\
= - 9989 - 2008 + 9989 - 192\\
= \left( { - 9989 + 9989} \right) - \left( {2008 + 192} \right)\\
= - 2200\\
b)187 + \left[ {921 - \left( {921 + 887} \right)} \right]\\
= 187 + 921 - 921 - 887\\
= 187 - 887\\
= - 700\\
c)44.179 + {20^2} - 79.44\\
= \left( {44.179 - 79.44} \right) + 400\\
= 400\\
d){3.4^2}:\left[ {500 - \left( {7.35 + 125} \right)} \right]\\
= 3.16:\left( {500 - 245 - 125} \right)\\
= 48:130\\
= \frac{{24}}{{65}}
\end{array}$