Sau khi thực hiện các phép tính: \(\left(-3,2\right).\dfrac{-15}{64}+\left(0,8-2\dfrac{4}{15}\right):3\dfrac{2}{3}\) , kết quả nhận được là
\(\dfrac{7}{20}\). \(\dfrac{9}{20}\). \(\dfrac{3}{10}\). \(\dfrac{14}{5}\). Hướng dẫn giải:\(\left(-3,2\right).\dfrac{-15}{64}+\left(0,8-2\dfrac{4}{15}\right):3\dfrac{2}{3}\)
\(=-\dfrac{16}{5}.\dfrac{-15}{64}+\left(\dfrac{4}{5}-\dfrac{34}{15}\right):\dfrac{11}{3}\)
\(=\dfrac{3}{4}+\left(\dfrac{12}{15}-\dfrac{34}{15}\right).\dfrac{3}{11}\)
\(=\dfrac{3}{4}-\dfrac{22}{15}.\dfrac{3}{11}\)
\(=\dfrac{3}{4}-\dfrac{2}{5}\)
\(=\dfrac{15}{20}-\dfrac{8}{20}\)
\(=\dfrac{7}{20}\).
