Решение:

3. Обратите десятичные дроби в обыкновенные, затем вычислите:

1. $$0,5 + \frac{1}{3} = \frac{1}{2} + \frac{1}{3} = \frac{3}{6} + \frac{2}{6} = \frac{5}{6}$$
2. $$0,7 + \frac{1}{6} = \frac{7}{10} + \frac{1}{6} = \frac{42}{60} + \frac{10}{60} = \frac{52}{60} = \frac{13}{15}$$
3. $$1,75 + \frac{4}{9} = 1\frac{75}{100} + \frac{4}{9} = 1\frac{3}{4} + \frac{4}{9} = 1\frac{27}{36} + \frac{16}{36} = 1\frac{43}{36} = 2\frac{7}{36}$$
4. $$1,5 + 2\frac{8}{15} = 1\frac{1}{2} + 2\frac{8}{15} = 1\frac{15}{30} + 2\frac{16}{30} = 3\frac{31}{30} = 4\frac{1}{30}$$
5. $$0,8 - \frac{1}{3} = \frac{8}{10} - \frac{1}{3} = \frac{4}{5} - \frac{1}{3} = \frac{12}{15} - \frac{5}{15} = \frac{7}{15}$$
6. $$2,4 - 1\frac{1}{6} = 2\frac{4}{10} - 1\frac{1}{6} = 2\frac{2}{5} - 1\frac{1}{6} = 2\frac{12}{30} - 1\frac{5}{30} = 1\frac{7}{30}$$
7. $$1,75 - \frac{4}{9} = 1\frac{75}{100} - \frac{4}{9} = 1\frac{3}{4} - \frac{4}{9} = 1\frac{27}{36} - \frac{16}{36} = 1\frac{11}{36}$$
8. $$4,5 - 2\frac{8}{15} = 4\frac{1}{2} - 2\frac{8}{15} = 4\frac{15}{30} - 2\frac{16}{30} = 3\frac{45}{30} - 2\frac{16}{30} = 1\frac{29}{30}$$