Biết kết quả của \(\begin{aligned} A &=\left[\left(\frac{1}{9}: \frac{8}{27}\right): \frac{16}{48}\right] \cdot \frac{81}{128} \end{aligned}\) là:

* Hướng dẫn giải

 \(\begin{aligned} A &=\left[\left(\frac{1}{9}: \frac{8}{27}\right): \frac{16}{48}\right] \cdot \frac{81}{128} \\ &=\left[\left(\frac{1}{9} \cdot \frac{27}{8}\right): \frac{16}{48}\right] \cdot \frac{81}{128} \\ &=\left(\frac{3}{8}: \frac{16}{48}\right) \cdot \frac{81}{128} \\ &=\frac{3}{8} \cdot \frac{48}{16} \cdot \frac{81}{128} \\ &=\frac{3.48 .81}{8.16 .128} \\ &=\frac{3.3 .16 .81}{8.16 .128} \\ &=\frac{3.3 .81}{8.128} \\ &=\frac{729}{1024} . \end{aligned}\)