Giải thích các bước giải:
$\begin{array}{l}
1)\\
a){\left( {1\dfrac{5}{9} + 4\dfrac{4}{9}} \right)^{10}}:{36^5}\\
= {\left( {1 + 4 + \left( {\dfrac{5}{9} + \dfrac{4}{9}} \right)} \right)^{10}}:{\left( {{6^2}} \right)^5}\\
= {6^{10}}:{6^{10}}\\
= 1\\
b){\left( {\dfrac{4}{7}} \right)^{12}}.{\left( { - 1,75} \right)^{13}} + 1,75\\
= {\left( {\dfrac{4}{7}} \right)^{12}}.{\left( {\dfrac{{ - 7}}{4}} \right)^{13}} + \dfrac{7}{4}\\
= {\left( {\dfrac{4}{7}.\dfrac{7}{4}} \right)^{12}}.\left( {\dfrac{{ - 7}}{4}} \right) + \dfrac{7}{4}\\
= \left( {\dfrac{{ - 7}}{4}} \right) + \dfrac{7}{4}\\
= 0\\
2)\\
a)A = 2\dfrac{3}{5}:\dfrac{5}{6} + 7\dfrac{2}{5}:\dfrac{5}{6} - 12\\
= \left( {2\dfrac{3}{5} + 7\dfrac{2}{5}} \right):\dfrac{5}{6} - 12\\
= \left( {2 + 7 + \dfrac{3}{5} + \dfrac{2}{5}} \right):\dfrac{5}{6} - 12\\
= 10:\dfrac{5}{6} - 12\\
= \dfrac{{60}}{5} - 12\\
= 12 - 12\\
= 0\\
b)B = \dfrac{{\dfrac{{12}}{7} - \dfrac{{20}}{9} + \dfrac{{28}}{{13}}}}{{\dfrac{{15}}{{14}} - \dfrac{{25}}{{18}} + \dfrac{{35}}{{26}}}}\\
= \dfrac{{4\left( {\dfrac{3}{7} - \dfrac{5}{9} + \dfrac{7}{{13}}} \right)}}{{\dfrac{5}{2}\left( {\dfrac{3}{7} - \dfrac{5}{9} + \dfrac{7}{{13}}} \right)}}\\
= \dfrac{4}{{\dfrac{5}{2}}}\\
= \dfrac{8}{5}
\end{array}$
