Выполните действия: 1) $$\frac{19}{28} + \frac{16}{28} - \frac{17}{28}$$; 2) $$4\frac{11}{14} - 2\frac{5}{14} + 1\frac{3}{14}$$; 3) $$1 - \frac{8}{17}$$; 4) $$4\frac{5}{9} - 2\frac{8}{9}$$.

1) $$\frac{19}{28} + \frac{16}{28} - \frac{17}{28} = \frac{19+16-17}{28} = \frac{35-17}{28} = \frac{18}{28} = \frac{9}{14}$$.

2) $$4\frac{11}{14} - 2\frac{5}{14} + 1\frac{3}{14} = (4 - 2 + 1) + (\frac{11}{14} - \frac{5}{14} + \frac{3}{14}) = 3 + \frac{11 - 5 + 3}{14} = 3 + \frac{9}{14} = 3\frac{9}{14}$$.

3) $$1 - \frac{8}{17} = \frac{17}{17} - \frac{8}{17} = \frac{17-8}{17} = \frac{9}{17}$$.

4) $$4\frac{5}{9} - 2\frac{8}{9} = 4 + \frac{5}{9} - 2 - \frac{8}{9} = 2 + \frac{5}{9} - \frac{8}{9} = 2 - \frac{3}{9} = 2 - \frac{1}{3} = 1 + \frac{3}{3} - \frac{1}{3} = 1 + \frac{2}{3} = 1\frac{2}{3}$$.