[tex] \frac{3}{7} \times \frac{2}{5} = \frac{6}{35} [/tex]

[tex] \frac{7}{13} \times \frac{39}{56} = \frac{3}{8} [/tex]

[tex]3 \frac{1}{9} \times 2 \frac{1}{7} = \frac{28}{9} \times \frac{15}{7} = \frac{20}{3} = 6 \frac{2}{3} [/tex]