2. Выполнить действия: 53 87 45 =+== 89 +2 1423 5 10 45 79 B) 17-3-2 20 4 3) 쥬 19 3 20 4 5 ✓3) 4+1 =z

Разбираемся с примерами на сложение и вычитание дробей. Важно привести дроби к общему знаменателю. A) \(\frac{5}{8} + \frac{3}{7} = \frac{5 \times 7}{8 \times 7} + \frac{3 \times 8}{7 \times 8} = \frac{35}{56} + \frac{24}{56} = \frac{59}{56}\) Б) \(1\frac{1}{5} + 2\frac{3}{10} = \frac{6}{5} + \frac{23}{10} = \frac{12}{10} + \frac{23}{10} = \frac{35}{10} = \frac{7}{2} = 3\frac{1}{2}\) B) \(\frac{17}{20} - \frac{3}{4} = \frac{17}{20} - \frac{3 \times 5}{4 \times 5} = \frac{17}{20} - \frac{15}{20} = \frac{2}{20} = \frac{1}{10}\) Г) \(\frac{5}{6} - \frac{2}{9} = \frac{5 \times 3}{6 \times 3} - \frac{2 \times 2}{9 \times 2} = \frac{15}{18} - \frac{4}{18} = \frac{11}{18}\) Д) \(\frac{4}{8} + \frac{5}{9} = \frac{4 \times 9}{8 \times 9} + \frac{5 \times 8}{9 \times 8} = \frac{36}{72} + \frac{40}{72} = \frac{76}{72} = \frac{19}{18}\) E) \(\frac{4}{7} + \frac{5}{9} = \frac{4 \times 9}{7 \times 9} + \frac{5 \times 7}{9 \times 7} = \frac{36}{63} + \frac{35}{63} = \frac{71}{63}\) Ж) \(\frac{19}{20} - \frac{3}{4} = \frac{19}{20} - \frac{3 \times 5}{4 \times 5} = \frac{19}{20} - \frac{15}{20} = \frac{4}{20} = \frac{1}{5}\) 3) \(4\frac{1}{6} + 1\frac{5}{12} = \frac{25}{6} + \frac{17}{12} = \frac{50}{12} + \frac{17}{12} = \frac{67}{12}\)