Thực hiện phép tính:

a) \[\frac{5}{4}\] – \[\frac{{11}}{6}\] × \[\frac{{12}}{{33}}\]

= \[\frac{5}{4}\] – \[\frac{2}{3}\]

= \[\frac{{15}}{{12}}\] – \[\frac{8}{{12}}\] = \[\frac{7}{{12}}\]

b) \[\frac{2}{7}\] + \[\frac{4}{{15}}\] : \[\frac{{18}}{3}\]

= \[\frac{2}{7}\] + \[\frac{2}{{45}}\]

= \[\frac{{90}}{{315}}\] + \[\frac{{14}}{{315}}\] = \[\frac{{104}}{{315}}\]

c)\[8\frac{5}{6}\] – \[2\frac{1}{2}\] × \[3\frac{1}{3}\]

= \[\frac{{53}}{6}\] – \[\frac{5}{2}\] × \[\frac{{10}}{3}\]

= \[\frac{{53}}{6}\] – \[\frac{{50}}{6}\] = \[\frac{3}{6}\] = \[\frac{1}{2}\]

d) \[9\frac{1}{2}\] – \[3\frac{3}{4}\] : \[2\frac{1}{4}\]

= \[\frac{{19}}{2}\] – \[\frac{{15}}{4}\] × \[\frac{4}{9}\]

= \[\frac{{19}}{2}\] – \[\frac{5}{3}\] = \[\frac{{57}}{6}\] – \[\frac{{10}}{6}\] = \[\frac{{47}}{6}\]