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МатематикаВопрос:
Задание 120. Приведите дроби к данному знаменателю и сравните их.
Ответ:
Задание 120.
Приводим дроби к общему знаменателю и сравниваем.
| Знаменатель | Дробь | Дробь | Сравнение |
| 1) 6 | \(\frac{1}{2}\) | \(\frac{1 \cdot 3}{2 \cdot 3} = \frac{3}{6}\) | |
| 2) 10 | \(\frac{1}{2}\) | \(\frac{1 \cdot 5}{2 \cdot 5} = \frac{5}{10}\) | \(\frac{5}{10} > \frac{2}{10}\) |
| \(\frac{1}{2}\) | \(\frac{1 \cdot 5}{2 \cdot 5} = \frac{5}{10}\) | ||
| 3) 20 | \(\frac{3}{4}\) | \(\frac{3 \cdot 5}{4 \cdot 5} = \frac{15}{20}\) | |
| 4) 28 | \(\frac{2}{7}\) | \(\frac{2 \cdot 4}{7 \cdot 4} = \frac{8}{28}\) | \(\frac{15}{20} > \frac{4}{20}\) |
| \(\frac{8}{28} < \frac{?}{28}\) | |||
| 5) 12 | \(\frac{5}{6}\) | \(\frac{5 \cdot 2}{6 \cdot 2} = \frac{10}{12}\) | |
| 6) 35 | \(\frac{2}{5}\) | \(\frac{2 \cdot 7}{5 \cdot 7} = \frac{14}{35}\) | |
| 7) 24 | \(\frac{7}{8}\) | \(\frac{7 \cdot 3}{8 \cdot 3} = \frac{21}{24}\) | |
| 8) 60 | \(\frac{7}{12}\) | \(\frac{7 \cdot 5}{12 \cdot 5} = \frac{35}{60}\) | |
| 9) 100 | \(\frac{3}{5}\) | \(\frac{3 \cdot 20}{5 \cdot 20} = \frac{60}{100}\) |
Задание 121.
Приведите дроби к данному знаменателю и найдите сумму этих дробей.
| Дробь | Дробь | |
| 1) | \(\frac{1}{2}\) | \(\frac{1 \cdot 3}{2 \cdot 3} = \frac{3}{6}\) |
| \(\frac{1}{3}\) | \(\frac{1 \cdot 2}{3 \cdot 2} = \frac{2}{6}\) | |
| 2) | \(\frac{1}{2}\) | \(\frac{1 \cdot 2}{2 \cdot 2} = \frac{2}{4}\) |
| \(\frac{1}{5}\) | \(\frac{1 \cdot 1}{5 \cdot 1} = \frac{1}{5}\) | |
| 3) | \(\frac{3}{4}\) | \(\frac{3 \cdot 5}{4 \cdot 5} = \frac{15}{20}\) |
| \(\frac{1}{5}\) | \(\frac{1 \cdot 4}{5 \cdot 4} = \frac{4}{20}\) | |
| 4) | \(\frac{1}{2}\) | \(\frac{1 \cdot 7}{2 \cdot 7} = \frac{7}{14}\) |
| \(\frac{1}{7}\) | \(\frac{1 \cdot 2}{7 \cdot 2} = \frac{2}{14}\) | |
| 5) | \(\frac{3}{4}\) | \(\frac{3 \cdot 3}{4 \cdot 3} = \frac{9}{12}\) |
| \(\frac{5}{6}\) | \(\frac{5 \cdot 2}{6 \cdot 2} = \frac{10}{12}\) | |
| 6) | \(\frac{3}{7}\) | \(\frac{3 \cdot 15}{7 \cdot 15} = \frac{45}{105}\) |
| \(\frac{5}{6}\) | \(\frac{5 \cdot 7}{6 \cdot 7} = \frac{35}{42}\) | |
| 7) | \(\frac{5}{6}\) | \(\frac{5 \cdot 15}{6 \cdot 15} = \frac{75}{90}\) |
| \(\frac{8}{15}\) | \(\frac{8 \cdot 6}{15 \cdot 6} = \frac{48}{90}\) | |
| 8) | \(\frac{8}{15}\) | \(\frac{8 \cdot 4}{15 \cdot 4} = \frac{32}{60}\) |
| \(\frac{7}{20}\) | \(\frac{7 \cdot 3}{20 \cdot 3} = \frac{21}{60}\) | |
| 9) | \(\frac{7}{20}\) | \(\frac{7 \cdot 1}{20 \cdot 1} = \frac{7}{20}\) |
| \(\frac{3}{5}\) | \(\frac{3 \cdot 4}{5 \cdot 4} = \frac{12}{20}\) |
