Контрольные задания
Вопрос:Фото задания: 14. Выполните сложение или вычитание: 1/2 + 3/8; 2/7 + 5/14; 3/5 + 4/15; 1/8 + 3/16; 2/9 + 5/18; 8/13 − 1/26; 7/15 − 7/30;…Фото задания

Ответ:

Приводим дроби к общему знаменателю, выполняем сложение или вычитание числителей и сокращаем результат.

  1. \(\frac{1}{2}+\frac{3}{8}=\frac{4}{8}+\frac{3}{8}=\frac{7}{8}\)
  2. \(\frac{2}{7}+\frac{5}{14}=\frac{4}{14}+\frac{5}{14}=\frac{9}{14}\)
  3. \(\frac{3}{5}+\frac{4}{15}=\frac{9}{15}+\frac{4}{15}=\frac{13}{15}\)
  4. \(\frac{1}{8}+\frac{3}{16}=\frac{2}{16}+\frac{3}{16}=\frac{5}{16}\)
  5. \(\frac{2}{9}+\frac{5}{18}=\frac{4}{18}+\frac{5}{18}=\frac{1}{2}\)
  6. \(\frac{8}{13}-\frac{1}{26}=\frac{16}{26}-\frac{1}{26}=\frac{15}{26}\)
  7. \(\frac{7}{15}-\frac{7}{30}=\frac{14}{30}-\frac{7}{30}=\frac{7}{30}\)
  8. \(\frac{2}{19}-\frac{1}{38}=\frac{4}{38}-\frac{1}{38}=\frac{3}{38}\)
  9. \(\frac{5}{7}-\frac{3}{14}=\frac{10}{14}-\frac{3}{14}=\frac{1}{2}\)
  10. \(\frac{4}{21}-\frac{1}{7}=\frac{4}{21}-\frac{3}{21}=\frac{1}{21}\)
  11. \(\frac{7}{20}+\frac{11}{50}=\frac{35}{100}+\frac{22}{100}=\frac{57}{100}\)
  12. \(\frac{5}{9}-\frac{1}{3}=\frac{5}{9}-\frac{3}{9}=\frac{2}{9}\)
  13. \(\frac{11}{40}+\frac{17}{120}=\frac{33}{120}+\frac{17}{120}=\frac{5}{12}\)
  14. \(\frac{17}{33}-\frac{5}{22}=\frac{34}{66}-\frac{15}{66}=\frac{19}{66}\)
  15. \(\frac{27}{76}-0=\frac{27}{76}\)
  16. \(\frac{9}{20}+\frac{5}{8}=\frac{18}{40}+\frac{25}{40}=\frac{43}{40}\)
  17. \(\frac{2}{7}+\frac{13}{28}=\frac{8}{28}+\frac{13}{28}=\frac{3}{4}\)
  18. \(\frac{5}{13}-\frac{14}{39}=\frac{15}{39}-\frac{14}{39}=\frac{1}{39}\)
  19. \(\frac{5}{8}-\frac{2}{7}=\frac{35}{56}-\frac{16}{56}=\frac{19}{56}\)
  20. \(\frac{3}{4}+\frac{5}{12}=\frac{9}{12}+\frac{5}{12}=\frac{7}{6}\)
  21. \(\frac{15}{23}-\frac{27}{46}=\frac{30}{46}-\frac{27}{46}=\frac{3}{46}\)
  22. \(\frac{9}{25}-\frac{14}{117}=\frac{1053}{2925}-\frac{350}{2925}=\frac{703}{2925}\)
  23. \(\frac{17}{35}-\frac{13}{28}=\frac{68}{140}-\frac{65}{140}=\frac{3}{140}\)
  24. \(1-\frac{2}{7}=\frac{5}{7}\)
  25. \(\frac{13}{40}-\frac{11}{60}=\frac{39}{120}-\frac{22}{120}=\frac{17}{120}\)
  26. \(\frac{5}{12}+\frac{3}{4}=\frac{5}{12}+\frac{9}{12}=\frac{7}{6}\)