Tính biểu thức. a) 4/3 + 1/6 b) 5/8 − 1/4

a) \(\frac{4}{3}\,\, + \,\,\frac{1}{6}\)

\[ = \frac{8}{6} + \frac{1}{6}\]\[ = \frac{9}{6} = \frac{3}{2}\]

b) \(\frac{5}{8}\,\, - \,\,\frac{1}{4}\)

\[ = \frac{5}{8} - \frac{2}{8}\]\[ = \frac{3}{8}\]

c) \(\frac{5}{7}\,\, \times \,\,\frac{{14}}{{25}}\)

\[ = \frac{{\not 5 \times \not 7 \times 2}}{{\not 7 \times \not 5 \times 5}}\]\[ = \frac{2}{5}\]

d) \(\frac{6}{{18}}\,\,:\,\,\frac{5}{9}\)

\[ = \frac{6}{{18}} \times \frac{9}{5}\] \[ = \frac{{3 \times \not 2 \times \not 9}}{{\not 9 \times \not 2 \times 5}}\]\[ = \frac{3}{5}\]