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

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