Question

Помогите пожалуйста решить!!! Очень нужно!!!

Answer 1

$1) \frac{2}{5} + \frac{7}{10} = \frac{4}{10} + \frac{7}{10} = \frac{4 + 7}{10} = \frac{11}{10} = 1 \frac{1}{10} \\ 2) \frac{5}{6} + \frac{2}{3} = \frac{5}{6} + \frac{4}{6} = \frac{5 + 9}{6} = \frac{14}{6} = 2 \frac{2}{6} = 2 \frac{1}{3} \\ 3) \frac{8}{15} + \frac{4}{5} = \frac{8}{15} + \frac{12}{15} = \frac{8 + 12}{15} = \frac{20}{15} = 1 \frac{5}{15} = 1 \frac{1}{3} \\ 4) \frac{7}{12} + \frac{2}{3} = \frac{7}{12} + \frac{8}{12} = \frac{7 + 8}{12} = \frac{15}{12} = 1 \frac{3}{12} = 1 \frac{1}{4}$