[4\(\dfrac{1}{5}\) - 2\(\dfrac{2}{5}\)] x 8\(\dfrac{5}{6}\)
= [\(\dfrac{21}{5}\) - \(\dfrac{12}{5}\)] x \(\dfrac{53}{6}\)
= \(\dfrac{9}{5}\) x \(\dfrac{53}{6}\)
= \(\dfrac{159}{10}\)
[5\(\dfrac{1}{3}\) - 2\(\dfrac{2}{3}\)]: \(\dfrac{3}{7}\)
= [\(\dfrac{16}{3}\) - \(\dfrac{8}{3}\)]: \(\dfrac{3}{7}\)
= \(\dfrac{8}{3}\) : \(\dfrac{3}{7}\)
= \(\dfrac{56}{9}\)
5\(\dfrac{3}{10}\) x \(\dfrac{1}{4}\): 2\(\dfrac{4}{7}\)
= \(\dfrac{53}{10}\) x \(\dfrac{1}{4}\): \(\dfrac{18}{7}\)
= \(\dfrac{53}{10}\) x \(\dfrac{1}{4}\) x \(\dfrac{7}{18}\)
= \(\dfrac{371}{720}\)
4\(\dfrac{3}{5}\) + 5\(\dfrac{3}{4}\)
= \(\dfrac{23}{5}\) + \(\dfrac{23}{4}\)
= 23 x (\(\dfrac{1}{5}\) + \(\dfrac{1}{4}\))
= 23 x \(\dfrac{9}{20}\)
= \(\dfrac{207}{20}\)
2\(\dfrac{4}{7}\) x 3\(\dfrac{5}{4}\)
= \(\dfrac{18}{7}\) x \(\dfrac{17}{4}\)
= \(\dfrac{153}{14}\)