Найдите значение выражений

16)
$\frac{7}{20} - ( - 3.7) - \frac{3}{25} = \frac{7}{20} + 3.7 - \frac{3}{25} = \frac{7}{20} + \frac{37}{10} - \frac{3}{25} = \frac{35}{100} + \frac{370}{100} - \frac{12}{100} = \frac{393}{100} = 3.93$
17)
$\frac{7}{20} - 5.05 - \frac{7}{2} = \frac{7}{20} - \frac{505}{100} - \frac{7}{2} = \frac{7}{20} - \frac{101}{20} - \frac{7}{2} = \frac{7}{20} - \frac{101}{20} - \frac{70}{20} = - \frac{164}{20} = - \frac{82}{10} = - 8.2$
18)
$\frac{7}{4} - 2.3 - \frac{3}{20} = \frac{7}{4} - \frac{23}{10} - \frac{3}{20} = \frac{35}{20} - \frac{46}{20} - \frac{3}{20} = - \frac{14}{20} = - \frac{7}{10} = - 0.7$
19)
$( - \frac{2}{5} ) - 3.04 - \frac{4}{25} = - \frac{2}{5} - 3 \frac{1}{25} - \frac{4}{25} = - \frac{10}{25} - \frac{76}{25} - \frac{4}{25} = - \frac{90}{25} = - \frac{18}{5} = - \frac{36}{10} = - 3.6$