Question

Thực hiện phép tính:

\(\dfrac{-5}{12}.\dfrac{2}{7}+\dfrac{7}{12}:\dfrac{-14}{3}\)

b) 1,4.\(\dfrac{15}{49}-\left(80\%+\dfrac{2}{3}\right):2\dfrac{1}{5}\)

Answer 1

a, \(\dfrac{-5}{12}.\dfrac{2}{7}+\dfrac{7}{12}:\dfrac{-14}{3}\)

\(=\dfrac{-5}{42}+\dfrac{7}{12}:\dfrac{-14}{3}\)

\(=\dfrac{-5}{42}+\dfrac{-1}{8}\)

\(=\dfrac{-41}{168}\)

b, \(1,4.\dfrac{15}{49}-\left(80\%+\dfrac{2}{3}\right):2\dfrac{1}{5}\)

\(=1,4.\dfrac{15}{49}-\dfrac{22}{15}:2\dfrac{1}{5}\)

\(=\dfrac{3}{7}-\dfrac{22}{15}:2\dfrac{1}{5}\)

\(=\dfrac{3}{7}-\dfrac{2}{3}\)

\(=\dfrac{-5}{21}\)

Answer 2

\(\dfrac{-5}{12}.\dfrac{2}{7}+\dfrac{7}{12}:\dfrac{-14}{3}=\dfrac{-5}{42}+\dfrac{-1}{8}\)

\(=\dfrac{-20}{168}+\dfrac{-8820}{168}=\dfrac{-8840}{168}=\dfrac{-1105}{21}\)

Answer 3

a, \(\dfrac{-5}{12}.\dfrac{2}{7}+\dfrac{7}{12}:\dfrac{-14}{3}\)

\(=\dfrac{-5}{42}+\dfrac{-1}{8}\)

\(=\dfrac{-41}{168}\)

b, \(1,4.\dfrac{15}{49}-\left(80\%+\dfrac{2}{3}\right):2\dfrac{1}{5}\)

\(=\dfrac{7}{5}.\dfrac{15}{49}-\left(\dfrac{4}{5}+\dfrac{2}{3}\right).\dfrac{5}{11}\)

\(=\dfrac{3}{7}-\dfrac{22}{15}.\dfrac{5}{11}\)

\(=\dfrac{3}{7}-\dfrac{2}{3}\)

\(=\dfrac{-5}{21}\)