Question

2 Thực​ hiêện​ phép​ tính : \(\dfrac{7}{9}.(1\dfrac{1}{6}-1:1\dfrac{1}{19}-\dfrac{1}{15})+4\dfrac{2}{5}:24\)

Answer 1

Ta có : \(\dfrac{7}{9}.\left(1\dfrac{1}{6}-1:1\dfrac{1}{19}-\dfrac{1}{15}\right)+4\dfrac{2}{5}:24\)

\(=\dfrac{7}{9}.\left(\dfrac{7}{6}-\dfrac{19}{20}-\dfrac{1}{15}\right)+\dfrac{22}{5}.\dfrac{1}{24}\)

=\(\dfrac{7}{9}.\left(\dfrac{70}{60}-\dfrac{57}{60}-\dfrac{4}{60}\right)+\dfrac{11}{60}\)

\(=\dfrac{7}{9}.\dfrac{3}{20}+\dfrac{11}{60}\)

\(=\dfrac{7}{60}+\dfrac{11}{60}=\dfrac{18}{60}=\dfrac{3}{10}\)