ГДЗ Математика 5 класс Дорофеев. 9.3 Сложение и вычитание смешанных дробей. Задание 795

ОТВЕТЫ К ЗАДАНИЯМ

Выполните сложение:
а)

2 \frac{3}{4} + 1 \frac{2}{3}

;

б)

8 \frac{3}{5} + 1 \frac{9}{10}

;

в)

\frac{7}{20} + 8 \frac{3}{4}

;

г)

12 \frac{5}{6} + \frac{4}{15}

;

д)

8 \frac{5}{6} + 2 \frac{3}{8}

;

е)

1 \frac{4}{5} + 3 \frac{11}{30}

2 \frac{3}{4} + 1 \frac{2}{3} = (2 + 1) + (\frac{3}{4} + \frac{2}{3}) = 3 + \frac{9 + 8}{12} = 3 + \frac{17}{12} = 3 + 1 \frac{5}{12} = (3 + 1) + \frac{5}{12} = 4 + \frac{5}{12} = 4 \frac{5}{12}

8 \frac{3}{5} + 1 \frac{9}{10} = (8 + 1) + (\frac{3}{5} + \frac{9}{10}) = 9 + \frac{6 + 9}{10} = 9 + \frac{15}{10} = 9 + 1 \frac{5}{10} = (9 + 1) + \frac{1}{2} = 10 \frac{1}{2}

\frac{7}{20} + 8 \frac{3}{4} = 8 + (\frac{7}{20} + \frac{3}{4}) = 8 + \frac{7 + 15}{20} = 8 + \frac{22}{20} = 8 + 1 \frac{2}{20} = (8 + 1) + \frac{1}{10} = 9 + \frac{1}{10} = 9 \frac{1}{10}

12 \frac{5}{6} + \frac{4}{15} = 12 + (\frac{5}{6} + \frac{4}{15}) = 12 + \frac{25 + 8}{30} = 12 + \frac{33}{30} = 12 + 1 \frac{3}{30} = (12 + 1) + \frac{1}{10} = 13 + \frac{1}{10} = 13 \frac{1}{10}

8 \frac{5}{6} + 2 \frac{3}{8} = (8 + 2) + (\frac{5}{6} + \frac{3}{8}) = 10 + \frac{20 + 9}{24} = 10 + \frac{29}{24} = 10 + 1 \frac{5}{24} = (10 + 1) + \frac{5}{24} = 11 + \frac{5}{24} = 11 \frac{5}{24}

1 \frac{4}{5} + 3 \frac{11}{30} = (1 + 3) + \frac{24 + 11}{30} = 4 + \frac{35}{30} = 4 + 1 \frac{5}{30} = (4 + 1) + \frac{1}{6} = 5 + \frac{1}{6} = 5 \frac{1}{6}