\(\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{5}{19}=-\frac{19}{20}.\frac{5}{19}=-\frac{1}{4}\)
\(\left(\frac{1}{14}+\frac{1}{7}-\frac{-3}{35}\right).\frac{-4}{3}=\frac{3}{10}.-\frac{4}{3}=-\frac{4}{10}=-\frac{2}{5}\)
<=>(18/60-16/60-21/60).5/19
<=>-19/60.5/19
<=>-1/12
\(\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{5}{19}\)
\(=\left(\frac{18}{60}-\frac{16}{60}-\frac{21}{60}\right).\frac{5}{9}\)
\(=-\frac{19}{60}.\frac{5}{9}\)
\(=-\frac{19}{108}\)
\(\left(\frac{1}{14}+\frac{1}{7}-\frac{-3}{35}\right).\frac{-4}{3}\)
\(\left(\frac{1}{14}+\frac{1}{7}+\frac{3}{35}\right).\frac{-4}{3}\)
\(=\left(\frac{5}{70}+\frac{10}{70}+\frac{6}{70}\right).\frac{-4}{3}\)
\(=\frac{3}{10}.\frac{-4}{3}\)
\(=-\frac{2}{5}\)