Đáp án:
1) a) \( - \dfrac{5}{3}\)
Giải thích các bước giải:
\(\begin{array}{l}
C1:\\
a)\dfrac{5}{9}:\dfrac{{12}}{5} - \dfrac{{41}}{9}:\dfrac{{12}}{5}\\
= \left( {\dfrac{{5 - 41}}{9}} \right):\dfrac{{12}}{5} = - 4:\dfrac{{12}}{5}\\
= - \dfrac{5}{3}\\
b)8.\dfrac{1}{{64}} - \dfrac{{33}}{5} - \dfrac{5}{8} + \dfrac{{23}}{5}\\
= \dfrac{{1 - 5}}{8} + \dfrac{{ - 33 + 23}}{5}\\
= - \dfrac{1}{2} - 2 = - \dfrac{5}{2}\\
2)b){\left( {x - \dfrac{1}{5}} \right)^3}.2 = - 16,8 + \dfrac{4}{5}\\
\to {\left( {x - \dfrac{1}{5}} \right)^3}.2 = - 16\\
\to {\left( {x - \dfrac{1}{5}} \right)^3} = - 8\\
\to x - \dfrac{1}{5} = - 2\\
\to x = - \dfrac{9}{5}
\end{array}\)
