Вычислите 10/39:5/13, 2/15*3, 4целые 4/9:2целые 2/15, (2целые 1/2)в кубе

1) $\frac{10}{39} : \frac{5}{13} = \frac{10}{39} * \frac{13}{5} = \frac{2}{3}$

2) $\frac{2}{15} *3= \frac{2}{5}$

3) $4 \frac{4}{9} :2 \frac{2}{15} = \frac{40}{9} : \frac{32}{15} = \frac{40}{9} * \frac{15}{32} = \frac{5}{3} * \frac{5}{4} = \frac{25}{12} =2 \frac{1}{12}$

4) $(2 \frac{1}{2} )^3=( \frac{5}{2} )^3= \frac{125}{8}$