9. Выполните сложение: a) 3 + 2 б) 4 + 1 в) 6 + 9 : 4 3 9 6 7 21 б) 3 + 2 г) 7 + 3 д) 11 + 6 : 10 15 15 40 20 15

Ответ: a) 17/12; б) 5/6; в) 3/7; г) 37/60; д) 43/60

а) \(\frac{3}{4} + \frac{2}{3} = \frac{9}{12} + \frac{8}{12} = \frac{17}{12}\)

б) \(\frac{4}{9} + \frac{1}{6} = \frac{8}{18} + \frac{3}{18} = \frac{11}{18}\)

в) \(\frac{6}{7} + \frac{9}{21} = \frac{18}{21} + \frac{9}{21} = \frac{27}{21} = \frac{9}{7}\)

г) \(\frac{3}{10} + \frac{2}{15} = \frac{9}{30} + \frac{4}{30} = \frac{13}{30}\)

д) \(\frac{7}{15} + \frac{3}{40} = \frac{56}{120} + \frac{9}{120} = \frac{65}{120} = \frac{13}{24}\)

е) \(\frac{11}{20} + \frac{6}{15} = \frac{33}{60} + \frac{24}{60} = \frac{57}{60} = \frac{19}{20}\)

Ответ: a) 17/12; б) 5/6; в) 3/7; г) 37/60; д) 43/60