[tex]a) \frac{3}{10} \times \frac{28}{9} \times 2 \frac{2}{14} = \frac{3}{10} \times \frac{2}{9} \times 2 \times 2 = \frac{1}{10} \times \frac{2}{3} \times 2 \times 2 = \frac{1}{5} \times \frac{2}{3} \times 2 = \frac{1}{5 } \times \frac{2}{3} \times \frac{2}{1} = \frac{1 \times 2 \times 2}{5 \times 3 \times 1} = \frac{4}{15} [/tex]
[tex]b) \frac{2}{5} \times ( \frac{4}{28 } - \frac{3}{42} ) = \frac{2}{5} \times \frac{1}{14} = \frac{1}{5} \times \frac{1}{7} = \frac{1}{35} [/tex]
