[tex]a) \: \frac{4}{5} \times \frac{3}{7} = \frac{12}{35} [/tex]
[tex]b) \: \frac{14}{9} \times \frac{6}{21} = \frac{84}{189} [/tex]
[tex]c) \: 9 \times \frac{5}{12} = \frac{45}{12} [/tex]
[tex]d) \: 2 \frac{4}{5} \times \frac{15}{28} = \frac{2 \times 5 + 4}{5} \times \frac{15}{28} \\ = \frac{14}{5} \times \frac{15}{28} = \frac{210}{140} [/tex]
[tex]e) \: 2 \frac{2}{5} \times 2 \frac{1}{12} = \frac{2 \times 5 + 2}{5} \times \frac{2 \times 12 + 1}{12} \\ = \frac{12}{5} \times \frac{25}{12} = \frac{300}{60} [/tex]
