I. thực hiện phép tính
a. \(5-2\times\left(\dfrac{-1}{2}\right)^2\)
b. \(\left(4-\dfrac{1}{2}\right)^3+\dfrac{1}{2}\)
c. \(5\dfrac{5}{27}+\dfrac{7}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\)
d. \(19+\dfrac{3}{8}\times27\dfrac{1}{5}\times51\dfrac{1}{5}\times\dfrac{3}{8}\)
e. \(35\dfrac{1}{6}\div\dfrac{-4}{5}-45\dfrac{1}{6}\div\dfrac{-4}{5}\)