Найдите значение выражений

16)
$\frac{0.8}{1 + \frac{1}{7} } = \frac{0.8}{ \frac{7}{7} + \frac{1}{7} } = \frac{0.8}{ \frac{8}{7} } = 0.8 \times \frac{7}{8} = 0.1 \times 7 = 0.7$
17)
$\frac{0.8}{1 + \frac{1}{4} } = \frac{0.8}{ \frac{4}{4} + \frac{1}{4} } = \frac{0.8}{ \frac{5}{4} } = 0.8 \times \frac{4}{5} = \frac{8}{10} \times \frac{4}{5} = \frac{4}{5} \times \frac{4}{5} = \frac{16}{25} = \frac{64}{100} = 0.64$
18)
$\frac{1.4}{1 + \frac{1}{13} } = \frac{1.4}{ \frac{13}{13} + \frac{1}{13} } = \frac{1.4}{ \frac{14}{13} } = 1.4 \times \frac{13}{14} = 0.1 \times 13 = 1.3$
19)
$\frac{0.9}{ 1 + \frac{1}{8} } = \frac{0.9}{ \frac{8}{8} + \frac{1}{8} } = \frac{0.9}{ \frac{9}{8} } = 0.9 \times \frac{8}{9} = 0.1 \times 8 = 0.8$