Question

Tính nhanh nếu có thể

(-2)\(\left(\dfrac{-38}{21}\right)\left(\dfrac{-7}{4}\right)\left(\dfrac{-3}{8}\right)\)

(\(\dfrac{11}{12}:\dfrac{33}{16}\))\(\dfrac{3}{5}\)

\(\dfrac{7}{23}\left[\left(-\dfrac{8}{6}\right)-\dfrac{45}{18}\right]\)

 

Answer 1

a: \(=2\cdot\dfrac{7}{4}\cdot\dfrac{38}{21}\cdot\dfrac{3}{8}=\dfrac{3}{4}\cdot\dfrac{19}{2}\cdot\dfrac{1}{3}=\dfrac{19}{8}\)

b: \(=\left(\dfrac{11}{12}\cdot\dfrac{16}{33}\right)\cdot\dfrac{3}{5}=\left(\dfrac{1}{3}\cdot\dfrac{4}{3}\right)\cdot\dfrac{3}{5}=\dfrac{1}{3}\cdot\dfrac{4}{5}=\dfrac{4}{15}\)

c: \(=\dfrac{7}{23}\cdot\left[-\dfrac{24}{18}-\dfrac{45}{18}\right]=\dfrac{7}{23}\cdot\dfrac{-69}{18}=\dfrac{-3}{18}\cdot7=-\dfrac{7}{6}\)