Tính:

a) \(\frac{5}{{72}}:\frac{3}{8}:\frac{{16}}{9}\)

= \(\frac{5}{{72}} \times \frac{8}{3} \times \frac{9}{{16}}\)

= \(\frac{5}{{27}} \times \frac{9}{{16}}\)

= \(\frac{5}{{48}}\)

b) \(\frac{9}{{14}}:\frac{{18}}{{11}} \times \frac{{20}}{7}:\frac{5}{6}\)

= \(\frac{9}{{14}} \times \frac{{11}}{{18}} \times \frac{{20}}{7} \times \frac{6}{5}\)

= \(\frac{{11}}{{28}} \times \frac{{20}}{7} \times \frac{6}{5}\)

= \(\frac{{55}}{{49}} \times \frac{6}{5}\) = \(\frac{{66}}{{49}}\)

a) \(\frac{5}{8} \times \frac{4}{3} = \frac{{10}}{{12}}\)

Giải thích

\(\frac{{10}}{{12}}:\frac{5}{8} = \frac{4}{3}\)

b) \(\frac{7}{{11}} \times \frac{{22}}{{15}} = \frac{{14}}{{15}}\)

Giải thích

\(\frac{{14}}{{15}}:\frac{7}{{11}} = \frac{{22}}{{15}}\)

c) \(\frac{3}{4} \times \frac{3}{4} = \frac{9}{{16}}\)

Giải thích

\(\frac{9}{{16}}:\frac{3}{4} = \frac{3}{4}\)

d) \(\frac{2}{3} \times \frac{5}{6} = \frac{{10}}{{18}}\)

Giải thích

\(\frac{{10}}{{18}}:\frac{5}{6} = \frac{2}{3}\)