Вычислите: 1) 21/40 : 3/4 2) 1 5/9 : 1 8/27 3) 5 : 15/16 4) 9/17 : 3

1) $\frac{21}{40} : \frac{3}{4} = \frac{21}{40} * \frac{4}{3} = \frac{7}{10} = 0,7$
2) $1 \frac{5}{9} : 1 \frac{8}{27} = \frac{14}{9} * \frac{27}{35} = \frac{42}{35} = 1 \frac{7}{35} = 1,2$
3) $5 : \frac{15}{16} = \frac{5}{1} * \frac{16}{15} = \frac{16}{3} = 5 \frac{1}{3}$
4) $\frac{9}{17} : 3 = \frac{9}{17} * \frac{1}{3} = \frac{3}{17}$