Контрольные задания
Вопрос:Фото задания: Вычислите дроби в левом столбце: 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; 2/19…Фото задания

Ответ:

  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. \(\frac{11}{40}+\frac{17}{120}=\frac{33}{120}+\frac{17}{120}=\frac{5}{12}\).