Задание 2 1) 120+8; 2) 313+67; 15 10 Найдите разность: 5 2 1)70-3; 6 2)8-620

Ответ:

1) \(12\frac{3}{8} + 8\frac{1}{6} = 12 + 8 + \frac{3}{8} + \frac{1}{6} = 20 + \frac{3 \cdot 3 + 1 \cdot 4}{24} = 20 + \frac{9 + 4}{24} = 20 + \frac{13}{24} = 20\frac{13}{24}\)

2) \(3\frac{13}{15} + 6\frac{7}{10} = 3 + 6 + \frac{13}{15} + \frac{7}{10} = 9 + \frac{13 \cdot 2 + 7 \cdot 3}{30} = 9 + \frac{26 + 21}{30} = 9 + \frac{47}{30} = 9 + 1\frac{17}{30} = 10\frac{17}{30}\)

Найдите разность:

1) \(7\frac{5}{6} - 3\frac{2}{3} = 7 - 3 + \frac{5}{6} - \frac{2}{3} = 4 + \frac{5 - 2 \cdot 2}{6} = 4 + \frac{5 - 4}{6} = 4 + \frac{1}{6} = 4\frac{1}{6}\)

2) \(8\frac{5}{12} - 6\frac{7}{20} = 8 - 6 + \frac{5}{12} - \frac{7}{20} = 2 + \frac{5 \cdot 5 - 7 \cdot 3}{60} = 2 + \frac{25 - 21}{60} = 2 + \frac{4}{60} = 2 + \frac{1}{15} = 2\frac{1}{15}\)

Ответ: 1) \(20\frac{13}{24}\); 2) \(10\frac{17}{30}\); 1) \(4\frac{1}{6}\); 2) \(2\frac{1}{15}\)