80. Сложите дроби: а) 1/2 + 1/4; б) 2/3 + 1/6; в) 7/12 + 1/2; г) 1/8 + 3/4; д) 1/2 + 3/8; е) 3/5 + 1/10; ж) 2/3 + 1/12; з) 5/8 + 5/24.

а) \(\frac{1}{2}+\frac{1}{4}=\frac{2}{4}+\frac{1}{4}=\frac{3}{4}\).

б) \(\frac{2}{3}+\frac{1}{6}=\frac{4}{6}+\frac{1}{6}=\frac{5}{6}\).

в) \(\frac{7}{12}+\frac{1}{2}=\frac{7}{12}+\frac{6}{12}=\frac{13}{12}=1\frac{1}{12}\).

г) \(\frac{1}{8}+\frac{3}{4}=\frac{1}{8}+\frac{6}{8}=\frac{7}{8}\).

д) \(\frac{1}{2}+\frac{3}{8}=\frac{4}{8}+\frac{3}{8}=\frac{7}{8}\).

е) \(\frac{3}{5}+\frac{1}{10}=\frac{6}{10}+\frac{1}{10}=\frac{7}{10}\).

ж) \(\frac{2}{3}+\frac{1}{12}=\frac{8}{12}+\frac{1}{12}=\frac{9}{12}=\frac{3}{4}\).

з) \(\frac{5}{8}+\frac{5}{24}=\frac{15}{24}+\frac{5}{24}=\frac{20}{24}=\frac{5}{6}\).