Контрольные задания
Вопрос:Фото задания: Вычислите: 2/7 + 3/8; 3/13 − 6/8; 6/15 − 7/11; 9/5 − 10/7; 7/17 − 5/9; 8/9 + 2/11; 6/2 − 10/15; 3/10 − 7/6; 10/20 − 6/18; 6/8…Фото задания

Ответ:

  1. Находим общий знаменатель: \(\frac{2}{7}+\frac{3}{8}=\frac{16}{56}+\frac{21}{56}=\frac{37}{56}\).
  2. \(\frac{3}{13}-\frac{6}{8}=\frac{3}{13}-\frac{3}{4}=\frac{12}{52}-\frac{39}{52}=-\frac{27}{52}\).
  3. Сокращаем первую дробь: \(\frac{6}{15}-\frac{7}{11}=\frac{2}{5}-\frac{7}{11}=\frac{22}{55}-\frac{35}{55}=-\frac{13}{55}\).
  4. \(\frac{9}{5}-\frac{10}{7}=\frac{63}{35}-\frac{50}{35}=\frac{13}{35}\).
  5. \(\frac{7}{17}-\frac{5}{9}=\frac{63}{153}-\frac{85}{153}=-\frac{22}{153}\).
  6. \(\frac{8}{9}+\frac{2}{11}=\frac{88}{99}+\frac{18}{99}=\frac{106}{99}\).
  7. \(\frac{6}{2}-\frac{10}{15}=3-\frac{2}{3}=\frac{7}{3}\).
  8. \(\frac{3}{10}-\frac{7}{6}=\frac{9}{30}-\frac{35}{30}=-\frac{26}{30}=-\frac{13}{15}\).
  9. \(\frac{10}{20}-\frac{6}{18}=\frac{1}{2}-\frac{1}{3}=\frac{1}{6}\).
  10. \(\frac{6}{8}+\frac{1}{16}=\frac{12}{16}+\frac{1}{16}=\frac{13}{16}\).
  11. \(\frac{5}{11}-\frac{6}{5}=\frac{25}{55}-\frac{66}{55}=-\frac{41}{55}\).
  12. \(\frac{2}{25}+\frac{6}{13}=\frac{26}{325}+\frac{150}{325}=\frac{176}{325}\).
  13. \(\frac{4}{13}+\frac{6}{11}=\frac{44}{143}+\frac{78}{143}=\frac{122}{143}\).
  14. \(\frac{1}{10}-\frac{3}{14}=\frac{7}{70}-\frac{15}{70}=-\frac{8}{70}=-\frac{4}{35}\).
  15. \(\frac{2}{11}-\frac{3}{17}=\frac{34}{187}-\frac{33}{187}=\frac{1}{187}\).