Đáp án:
$\begin{array}{l}
a)\dfrac{{ - 7}}{{25}}.\dfrac{{11}}{{13}} + \dfrac{7}{{25}}.\dfrac{{ - 2}}{{13}} - \dfrac{{18}}{{25}}\\
= \dfrac{7}{{25}}.\left( {\dfrac{{ - 11}}{{13}} - \dfrac{2}{{13}}} \right) - \dfrac{{18}}{{25}}\\
= \dfrac{7}{{25}}.\dfrac{{ - 13}}{{13}} - \dfrac{{18}}{{25}}\\
= \dfrac{{ - 7}}{{25}} - \dfrac{{18}}{{25}}\\
= \dfrac{{ - 25}}{{25}}\\
= - 1\\
b)\left( {\dfrac{5}{7}.0,6 - 5:3\dfrac{1}{2}} \right).\left( {40\% - 1,4} \right).{\left( { - 2} \right)^3}\\
= \left( {\dfrac{5}{7}.\dfrac{3}{5} - 5:\dfrac{7}{2}} \right).\left( {\dfrac{2}{5} - \dfrac{7}{5}} \right).\left( { - 8} \right)\\
= \left( {\dfrac{5}{7}.\dfrac{3}{5} - \dfrac{5}{7}.2} \right).\dfrac{{ - 5}}{5}.\left( { - 8} \right)\\
= \left( {\dfrac{3}{5} - 2} \right).\dfrac{5}{7}.\left( { - 1} \right).\left( { - 8} \right)\\
= \dfrac{{ - 7}}{5}.\dfrac{5}{7}.8\\
= - 8\\
c)\left( {4\dfrac{3}{{17}} - 3\dfrac{4}{7} + 5\dfrac{6}{{13}}} \right) - \left( {2\dfrac{3}{{17}} - 1\dfrac{7}{{13}}} \right)\\
= \left( {4 + \dfrac{3}{{17}} - 3 - \dfrac{4}{7} + 5 + \dfrac{6}{{13}}} \right)\\
- \left( {2 + \dfrac{3}{{17}} - 1 - \dfrac{7}{{13}}} \right)\\
= 6 + \dfrac{3}{{17}} - \dfrac{4}{7} + \dfrac{6}{{13}} - 1 - \dfrac{3}{{17}} + \dfrac{7}{{13}}\\
= 5 - \dfrac{4}{7} + \dfrac{6}{{13}} + \dfrac{7}{{13}}\\
= 5 - \dfrac{4}{7} + 1\\
= 6 - \dfrac{4}{7}\\
= \dfrac{{38}}{7}\\
d)\dfrac{{27.18 + 27.103 - 120.27}}{{15.33 + 33.12}}\\
= \dfrac{{27.\left( {18 + 103 - 27} \right)}}{{33.\left( {15 + 12} \right)}}\\
= \dfrac{{27.94}}{{33.27}}\\
= \dfrac{{94}}{{33}}
\end{array}$
