Выполни действие: 13) 19 4/9 - 2 5/6 =

13) $19\frac{4}{9} - 2\frac{5}{6} = 19\frac{8}{18} - 2\frac{15}{18} = 18\frac{26}{18} - 2\frac{15}{18} = 16\frac{11}{18}$ 14) $22\frac{19}{45} - 11\frac{17}{45} = 11\frac{2}{45}$ 15) $\frac{16}{49} + \frac{25}{49} = \frac{41}{49}$ 16) $\frac{5}{28} - \frac{11}{63}$. Общий знаменатель 252: $\frac{45}{252} - \frac{44}{252} = \frac{1}{252}$ 17) $\frac{15}{17} + \frac{2}{17} = \frac{17}{17} = 1$ 18) $5\frac{7}{18} - \frac{13}{18} = 4\frac{25}{18} - \frac{13}{18} = 4\frac{12}{18} = 4\frac{2}{3}$ 19) $\frac{19}{20} + 4\frac{17}{50}$. Общий знаменатель 100: $\frac{95}{100} + 4\frac{34}{100} = 4\frac{129}{100} = 5\frac{29}{100}$ 20) $3 + \frac{11}{36} = 3\frac{11}{36}$ 21) $51\frac{3}{14} - 12\frac{5}{14} = 50\frac{17}{14} - 12\frac{5}{14} = 38\frac{12}{14} = 38\frac{6}{7}$ 22) $3\frac{16}{45} + \frac{7}{10}$. Общий знаменатель 90: $3\frac{32}{90} + \frac{63}{90} = 3\frac{95}{90} = 4\frac{5}{90} = 4\frac{1}{18}$ 23) $1 - \frac{15}{29} = \frac{29}{29} - \frac{15}{29} = \frac{14}{29}$ 24) $2\frac{8}{27} + 1\frac{4}{27} = 3\frac{12}{27} = 3\frac{4}{9}$