a) \(...=\dfrac{5}{6}-\dfrac{4}{15}=\dfrac{75}{90}-\dfrac{24}{90}=\dfrac{51}{90}\)
b) \(...=\dfrac{1}{2}-\dfrac{1}{5}=\dfrac{5}{10}-\dfrac{2}{10}=\dfrac{3}{10}\)
\(\dfrac{25}{30}\) - \(\dfrac{4}{15}\) = \(\dfrac{5}{6}\) - \(\dfrac{4}{15}\) = \(\dfrac{17}{30}\)
\(\dfrac{27}{54}\) - \(\dfrac{3}{15}\) = \(\dfrac{1}{2}\) - \(\dfrac{1}{5}\) = \(\dfrac{3}{10}\)
Bạn tự QĐMS nhé