Как решить? помогите! прошу! номер 280.

А) $\frac{1}{2} + \frac{3}{7} = \frac{7}{14} + \frac{6}{14} = \frac{13}{14}$

$\frac{1}{3} + \frac{1}{8} = \frac{8}{24} + \frac{3}{24} = \frac{11}{24}$

$\frac{5}{6} + \frac{1}{3} = \frac{5}{6} + \frac{2}{6} = \frac{7}{6}= 1 \frac{1}{6}$

б) $\frac{5}{24} + \frac{5}{6} = \frac{5}{24} + \frac{20}{24} = 1 \frac{1}{24}$

$\frac{1}{4} + \frac{1}{6} = \frac{3}{12} + \frac{2}{12} = \frac{5}{12}$

$\frac{1}{6} + \frac{2}{9} = \frac{6}{36} + \frac{8}{36} = \frac{14}{36} = \frac{7}{18}$