Question

1. thực hiện phép tính

a. \(\dfrac{1}{3}-\dfrac{1}{2}\)

b. \(16\dfrac{2}{7}:\dfrac{-3}{5}-28\dfrac{2}{7}:\dfrac{-3}{5}\)

c. \(-3^3-\left(\dfrac{-1}{3}\right):\dfrac{4}{15}\)

d. \(9.\left(\dfrac{-1}{3}\right)^3+\dfrac{1}{3}\)

Answer 1

a. \(\dfrac{1}{3}-\dfrac{1}{2}=\dfrac{2-3}{6}=\dfrac{-1}{6}\)

b. \(16\dfrac{2}{7}:\dfrac{-3}{5}-28\dfrac{2}{7}:\dfrac{-3}{5}\)

\(=\dfrac{-3}{5}.\left(16\dfrac{2}{7}-28\dfrac{2}{7}\right)\)

\(=\dfrac{-3}{5}.\left(-12\right)=\dfrac{36}{5}\)

c. \(-3^3-\left(\dfrac{-1}{3}\right):\dfrac{4}{15}\)

\(=\left(-27\right)-\dfrac{\left(-1\right).15}{3.4}\)

\(=\left(-27\right)+\dfrac{5}{4}=-27\dfrac{5}{4}\)

d. \(9.\left(\dfrac{-1}{3}\right)^3+\dfrac{1}{3}\)

\(=9.\dfrac{-1}{27}+\dfrac{1}{3}\)

\(=\dfrac{-1}{3}+\dfrac{1}{3}=0\)