Контрольные задания
Вопрос:Фото задания: Вычислите: 1/2 + 1/5; 2/3 − 1/4; 3/5 + 1/4; 5/6 − 2/9; 2/7 + 3/8; 7/9 − 1/6; 4/5 + 3/10; 5/8 − 1/3; 3/4 + 2/9; 7/10 − 3/8.Фото задания

Ответ:

  1. \(\frac12+\frac15=\frac5{10}+\frac2{10}=\frac7{10}\).
  2. \(\frac23-\frac14=\frac8{12}-\frac3{12}=\frac5{12}\).
  3. \(\frac35+\frac14=\frac{12}{20}+\frac5{20}=\frac{17}{20}\).
  4. \(\frac56-\frac29=\frac{15}{18}-\frac4{18}=\frac{11}{18}\).
  5. \(\frac27+\frac38=\frac{16}{56}+\frac{21}{56}=\frac{37}{56}\).
  6. \(\frac79-\frac16=\frac{14}{18}-\frac3{18}=\frac{11}{18}\).
  7. \(\frac45+\frac3{10}=\frac8{10}+\frac3{10}=\frac{11}{10}\).
  8. \(\frac58-\frac13=\frac{15}{24}-\frac8{24}=\frac7{24}\).
  9. \(\frac34+\frac29=\frac{27}{36}+\frac8{36}=\frac{35}{36}\).
  10. \(\frac7{10}-\frac38=\frac{28}{40}-\frac{15}{40}=\frac{13}{40}\).