16=\(-\dfrac{14}{6}+-\dfrac{5}{6}=\dfrac{\left(-14\right)+\left(-5\right)}{6}=-\dfrac{19}{6}\)
\(17=\dfrac{14}{4}-\dfrac{9}{4}=\dfrac{14-9}{4}=\dfrac{5}{4}\)
\(19=\dfrac{15}{4}-\dfrac{14}{4}=\dfrac{15-14}{4}=\dfrac{1}{4}\)
\(20=\dfrac{35}{21}+\dfrac{4}{21}=\dfrac{35+4}{21}=\dfrac{39}{21}=\dfrac{13}{7}\)
\(22=\dfrac{32}{60}-\dfrac{21}{6}=\dfrac{32-21}{60}=\dfrac{11}{60}\)
\(23=\dfrac{25}{40}-\dfrac{28}{40}=\dfrac{25-28}{40}=-\dfrac{3}{40}\)
\(25=-\dfrac{2}{18}+\dfrac{5}{18}=\dfrac{-2+5}{18}=\dfrac{3}{18}=\dfrac{1}{6}\)
\(26=\dfrac{9}{12}-\dfrac{5}{12}=\dfrac{9-5}{12}=\dfrac{4}{12}=\dfrac{1}{3}\)
\(28=-\dfrac{4}{7}+-\dfrac{1}{2}=-\dfrac{8}{14}+-\dfrac{7}{14}=\dfrac{\left(-8\right)+\left(-7\right)}{14}=-\dfrac{15}{14}\)
\(29=-\dfrac{35}{75}-\dfrac{9}{75}=\dfrac{\left(-35\right)-9}{75}=-\dfrac{44}{75}\)
\(16,\dfrac{-7}{3}+\dfrac{-5}{6}=\dfrac{-14}{6}+\dfrac{-5}{6}=\dfrac{\left(-14\right)+\left(-5\right)}{6}=\dfrac{-19}{6}\)
\(17,\dfrac{7}{2}-\dfrac{9}{4}=\dfrac{14}{4}-\dfrac{9}{4}=\dfrac{14-9}{4}=\dfrac{5}{4}\)
\(19,\dfrac{15}{4}-\dfrac{7}{2}=\dfrac{15}{4}-\dfrac{14}{4}=\dfrac{1}{4}\)
\(20,\dfrac{5}{3}-\dfrac{4}{-21}=\dfrac{35}{21}-\dfrac{-4}{21}=\dfrac{35-\left(-4\right)}{21}=\dfrac{39}{21}=\dfrac{13}{7}\)
\(22,\dfrac{8}{15}+\dfrac{-7}{20}=\dfrac{32}{60}+\dfrac{-21}{60}=\dfrac{32+-21}{60}=\dfrac{11}{60}\)
\(23,\dfrac{5}{8}-\dfrac{7}{10}=\dfrac{25}{40}-\dfrac{28}{40}=\dfrac{25-28}{40}=\dfrac{-3}{40}\)
\(25,\dfrac{-1}{9}+\dfrac{5}{18}=\dfrac{-2}{18}+\dfrac{5}{18}=\dfrac{-2+5}{18}=\dfrac{3}{18}=\dfrac{1}{6}\)
\(26,\dfrac{3}{4}-\dfrac{5}{12}=\dfrac{9}{12}-\dfrac{5}{12}=\dfrac{9-5}{12}=\dfrac{4}{12}=\dfrac{1}{3}\)
\(28,\dfrac{-4}{7}+\dfrac{-5}{10}=\dfrac{-40}{70}+\dfrac{-35}{70}=\dfrac{-75}{70}=\dfrac{-15}{14}\)
\(29,\dfrac{-7}{15}-\dfrac{3}{25}=\dfrac{-35}{75}-\dfrac{9}{75}=\dfrac{-35-9}{75}=\dfrac{-44}{75}\)