Question

в)5/21+11/14+9/28 г)19/15+6/5+13/30

Answer 1

Решение приложено на фото.

Answer 2

Ответ:

в) $\frac{5}{21} + \frac{11}{14} + \frac{9}{28} = \frac{5\cdot4}{21\cdot4} + \frac{11\cdot6}{14\cdot6} + \frac{9\cdot3}{28\cdot3} = \frac{20+66+27}{84} = \frac{113}{84} = 1\frac{29}{84}$

г) $\frac{19}{15} + \frac{6}{5} + \frac{13}{30} = \frac{19\cdot2}{15\cdot2} + \frac{6\cdot6}{5\cdot6} + \frac{13}{30} = \frac{38+36+13}{30} = \frac{87}{30} = 2\frac{27}{30} = 2\frac{9}{10} = 2,9$