Ta có: \(\left[6-3\cdot\left(-\dfrac{1}{3}\right)^2+\sqrt{\dfrac{1}{4}}\right]:\sqrt{0.\left(9\right)}\)
\(=\left(6-3\cdot\dfrac{1}{9}+\dfrac{1}{2}\right)\)
\(=6-\dfrac{1}{3}+\dfrac{1}{2}\)
\(=\dfrac{36}{6}-\dfrac{4}{6}+\dfrac{3}{6}\)
\(=\dfrac{35}{6}\)