Cho 

B

- Hướng dẫn giải

Đáp án B

$$\begin{gathered} C=\frac{4}{5}:\left(\frac{4}{5}.\frac{-5}{4}\right):\left(\frac{16}{25}-\frac{1}{5}\right) \\ =\frac{4}{5}:\left(-1\right):\frac{11}{25} \\ =\frac{4}{5}.\left(-1\right).\frac{25}{11} \\ =-\frac{20}{11} \end{gathered}$$

$$\begin{gathered} D=\frac{{\displaystyle \frac{15}{8}}-{\displaystyle \frac{15}{6}}-{\displaystyle \frac{15}{32}}+{\displaystyle \frac{15}{64}}}{3-{\displaystyle \frac{3}{2}}-{\displaystyle \frac{3}{4}}+{\displaystyle \frac{3}{8}}} \\ =\frac{15\left({\displaystyle \frac{1}{8}}-{\displaystyle \frac{1}{6}}-{\displaystyle \frac{1}{32}}+{\displaystyle \frac{1}{64}}\right)}{3.\left(1-{\displaystyle \frac{1}{2}}-{\displaystyle \frac{1}{4}}+{\displaystyle \frac{1}{8}}\right)} \\ =\frac{15.\left({\displaystyle \frac{-11}{192}}\right)}{3.{\displaystyle \frac{1}{8}}} \\ =5.\left(\frac{-11}{72}\right)=-\frac{55}{72} \end{gathered}$$

Vì $\frac{-55}{72}>-\frac{20}{11}$ nên D > C