Чтобы сложить обыкновенные дроби, нужно привести их к общему знаменателю, а потом сложить числители, оставив знаменатель без изменений. Если получается неправильная дробь (числитель больше знаменателя), её можно преобразовать в смешанное число, выделив целую часть.
Решения:
**Вариант 1**
1) $$\frac{2}{5} + \frac{1}{10} = \frac{4}{10} + \frac{1}{10} = \frac{5}{10} = \frac{1}{2}$$
2) $$\frac{5}{6} + \frac{2}{3} = \frac{5}{6} + \frac{4}{6} = \frac{9}{6} = \frac{3}{2} = 1\frac{1}{2}$$
3) $$\frac{3}{4} + \frac{7}{12} = \frac{9}{12} + \frac{7}{12} = \frac{16}{12} = \frac{4}{3} = 1\frac{1}{3}$$
4) $$\frac{15}{2} + \frac{4}{5} = \frac{75}{10} + \frac{8}{10} = \frac{83}{10} = 8\frac{3}{10}$$
5) $$\frac{5}{7} + \frac{3}{14} = \frac{10}{14} + \frac{3}{14} = \frac{13}{14}$$
6) $$\frac{3}{11} + \frac{6}{55} = \frac{15}{55} + \frac{6}{55} = \frac{21}{55}$$
7) $$\frac{1}{6} + \frac{1}{9} = \frac{3}{18} + \frac{2}{18} = \frac{5}{18}$$
8) $$\frac{1}{10} + \frac{1}{15} = \frac{3}{30} + \frac{2}{30} = \frac{5}{30} = \frac{1}{6}$$
9) $$\frac{2}{9} + \frac{1}{12} = \frac{8}{36} + \frac{3}{36} = \frac{11}{36}$$
10) $$\frac{1}{9} + \frac{1}{2} = \frac{2}{18} + \frac{9}{18} = \frac{11}{18}$$
**Вариант 2**
1) $$\frac{1}{4} + \frac{1}{12} = \frac{3}{12} + \frac{1}{12} = \frac{4}{12} = \frac{1}{3}$$
2) $$\frac{1}{6} + \frac{2}{3} = \frac{1}{6} + \frac{4}{6} = \frac{5}{6}$$
3) $$\frac{7}{8} + \frac{3}{4} = \frac{7}{8} + \frac{6}{8} = \frac{13}{8} = 1\frac{5}{8}$$
4) $$\frac{4}{7} + \frac{2}{21} = \frac{12}{21} + \frac{2}{21} = \frac{14}{21} = \frac{2}{3}$$
5) $$\frac{9}{12} + \frac{3}{4} = \frac{9}{12} + \frac{9}{12} = \frac{18}{12} = \frac{3}{2} = 1\frac{1}{2}$$
6) $$\frac{8}{9} + \frac{1}{3} = \frac{8}{9} + \frac{3}{9} = \frac{11}{9} = 1\frac{2}{9}$$
7) $$\frac{4}{5} + \frac{7}{15} = \frac{12}{15} + \frac{7}{15} = \frac{19}{15} = 1\frac{4}{15}$$
8) $$\frac{2}{21} + \frac{5}{14} = \frac{4}{42} + \frac{15}{42} = \frac{19}{42}$$
9) $$\frac{3}{18} + \frac{5}{27} = \frac{9}{54} + \frac{10}{54} = \frac{19}{54}$$
10) $$\frac{3}{15} + \frac{7}{20} = \frac{12}{60} + \frac{21}{60} = \frac{33}{60} = \frac{11}{20}$$
**Вариант 3**
1) $$\frac{3}{8} + \frac{7}{16} = \frac{6}{16} + \frac{7}{16} = \frac{13}{16}$$
2) $$\frac{5}{6} + \frac{11}{18} = \frac{15}{18} + \frac{11}{18} = \frac{26}{18} = \frac{13}{9} = 1\frac{4}{9}$$
3) $$\frac{7}{11} + \frac{5}{33} = \frac{21}{33} + \frac{5}{33} = \frac{26}{33}$$
4) $$\frac{8}{9} + \frac{2}{18} = \frac{16}{18} + \frac{2}{18} = \frac{18}{18} = 1$$
5) $$\frac{5}{8} + \frac{1}{15} = \frac{75}{120} + \frac{8}{120} = \frac{83}{120}$$
6) $$\frac{17}{17} + \frac{1}{34} = \frac{34}{34} + \frac{1}{34} = \frac{35}{34} = 1\frac{1}{34}$$
7) $$\frac{1}{4} + \frac{1}{6} = \frac{3}{12} + \frac{2}{12} = \frac{5}{12}$$
8) $$\frac{5}{8} + \frac{1}{10} = \frac{25}{40} + \frac{4}{40} = \frac{29}{40}$$
9) $$\frac{7}{9} + \frac{1}{6} = \frac{14}{18} + \frac{3}{18} = \frac{17}{18}$$
10) $$\frac{2}{21} + \frac{3}{14} = \frac{4}{42} + \frac{9}{42} = \frac{13}{42}$$
**Вариант 4**
1) $$\frac{1}{2} + \frac{1}{4} = \frac{2}{4} + \frac{1}{4} = \frac{3}{4}$$
2) $$\frac{2}{7} + \frac{7}{14} = \frac{4}{14} + \frac{7}{14} = \frac{11}{14}$$
3) $$\frac{2}{3} + \frac{7}{12} = \frac{8}{12} + \frac{7}{12} = \frac{15}{12} = \frac{5}{4} = 1\frac{1}{4}$$
4) $$\frac{4}{5} + \frac{3}{20} = \frac{16}{20} + \frac{3}{20} = \frac{19}{20}$$
5) $$\frac{4}{9} + \frac{7}{18} = \frac{8}{18} + \frac{7}{18} = \frac{15}{18} = \frac{5}{6}$$
6) $$\frac{9}{10} + \frac{4}{15} = \frac{27}{30} + \frac{8}{30} = \frac{35}{30} = \frac{7}{6} = 1\frac{1}{6}$$
7) $$\frac{5}{6} + \frac{3}{14} = \frac{35}{42} + \frac{9}{42} = \frac{44}{42} = \frac{22}{21} = 1\frac{1}{21}$$
8) $$\frac{5}{12} + \frac{1}{18} = \frac{15}{36} + \frac{2}{36} = \frac{17}{36}$$
9) $$\frac{1}{8} + \frac{3}{12} = \frac{3}{24} + \frac{6}{24} = \frac{9}{24} = \frac{3}{8}$$
10) $$\frac{3}{4} + \frac{1}{6} = \frac{9}{12} + \frac{2}{12} = \frac{11}{12}$$
