Question

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. \(35\dfrac{1}{6}\div\dfrac{-4}{5}-45\dfrac{1}{6}\div\dfrac{-4}{5}\)

Answer 1

a: \(=5-2\cdot\dfrac{1}{4}=5-\dfrac{1}{2}=\dfrac{9}{2}\)

b: \(=\left(\dfrac{7}{2}\right)^3+\dfrac{1}{2}=\dfrac{343}{8}+\dfrac{1}{2}=\dfrac{347}{8}\)

c: \(=\left(5+\dfrac{5}{27}-\dfrac{5}{27}\right)+\left(\dfrac{7}{23}+\dfrac{16}{23}\right)-\dfrac{1}{2}=5+1-\dfrac{1}{2}=5+\dfrac{1}{2}=5.5\)

e: \(=\dfrac{-5}{4}\left(35+\dfrac{1}{6}-45-\dfrac{1}{6}\right)=\dfrac{-5}{4}\cdot\left(-10\right)=\dfrac{50}{4}=\dfrac{25}{2}\)