5.
a.
[tex] \frac{4}{9} \div \frac{2}{5} = \frac{4}{9} \times \frac{5}{2} = \frac{20}{18} = \frac{10}{9} [/tex]
b.
[tex]3 \times \frac{1}{2} = \frac{3 \times 2 + 1}{2} = \frac{7}{2} [/tex]
[tex] \frac{7}{2} \times \frac{5}{7} = \frac{35}{14} [/tex]
6.
a.
[tex] \frac{1}{3} + \frac{3}{4} = \frac{4 + 9}{12} = \frac{13}{12} [/tex]
b.
[tex]2 \times \frac{2}{7} = \frac{2 \times 7 + 2}{7} = \frac{16}{7} [/tex]
[tex]1 \times \frac{3}{5} = \frac{1 \times 5 + 3}{5} = \frac{8}{5} [/tex]
[tex] \frac{16}{7} - \frac{8}{5} = \frac{80 - 56}{35} = \frac{24}{35} [/tex]
