Tính: \(\left( {\dfrac{1}{2...

B

- Hướng dẫn giải

 \(\left( {\dfrac{1}{2}\sqrt {\dfrac{1}{2}} - \dfrac{3}{2}\sqrt 2 + \dfrac{4}{5}\sqrt {200} } \right):\dfrac{1}{8}\)

\(= \left( {\dfrac{1}{2} \cdot \dfrac{1}{2}\sqrt 2 - \dfrac{3}{2}\sqrt 2 + \dfrac{4}{5} \cdot 10\sqrt 2 } \right) \cdot 8\)

\(= 2\sqrt 2 - 12\sqrt 2 + 64\sqrt 2 = 54\sqrt 2 \)