a) [tex]\frac{\frac{3}{2}}{\frac{9}{4}}=\frac{\not3\,1}{\not2\,1}\cdot\frac{\not4\,2}{\not9\,3}=\frac{1\cdot2}{1\cdot3}=\boxed{\frac{2}{3}}[/tex]
b) [tex]\frac{\frac{3}{11}}{\frac{5}{11}}=\frac{3}{\not11\,1}\cdot\frac{\not11\,1}{5}=\frac{3\cdot1}{1\cdot5}=\boxed{\frac{3}{5}}[/tex]
c) [tex]\frac{\frac{5}{9}}{3}=\frac{5}{9}\cdot\frac{1}{3}=\frac{5\cdot1}{9\cdot3}=\boxed{\frac{5}{27}}[/tex]
d) [tex]\frac{\frac{4}{7}}{\frac{7}{8}}=\frac{4}{7}\cdot\frac{8}{7}=\frac{4\cdot8}{7\cdot7}=\boxed{\frac{32}{49}}[/tex]
