1. Вычислите: a) 2/5 + 4/3 б) 5/2 * 1/4 в) 1 2/7 * 1 1/4 г) 1 2/3 : 1 1/10

Решение:

1. а)\[ \frac{2}{5} + \frac{4}{3} = \frac{2 \times 3}{5 \times 3} + \frac{4 \times 5}{3 \times 5} = \frac{6}{15} + \frac{20}{15} = \frac{26}{15} = 1 \frac{11}{15} \]
2. б)\[ \frac{5}{2} \times \frac{1}{4} = \frac{5 \times 1}{2 \times 4} = \frac{5}{8} \]
3. в)\[ 1 \frac{2}{7} \times 1 \frac{1}{4} = \frac{9}{7} \times \frac{5}{4} = \frac{9 \times 5}{7 \times 4} = \frac{45}{28} = 1 \frac{17}{28} \]
4. г)\[ 1 \frac{2}{3} : 1 \frac{1}{10} = \frac{5}{3} : \frac{11}{10} = \frac{5}{3} \times \frac{10}{11} = \frac{5 \times 10}{3 \times 11} = \frac{50}{33} = 1 \frac{17}{33} \]

Ответ:

• а) \(1 \frac{11}{15}\)
• б) \(\frac{5}{8}\)
• в) \(1 \frac{17}{28}\)
• г) \(1 \frac{17}{33}\)