1. Выполните действия: 1) $$1 \frac{5}{6} - 1 \frac{7}{12}$$; 2) $$5 \frac{9}{42} - 3 \frac{5}{42}$$; 3) $$1 - \frac{27}{43}$$; 4) $$7 \frac{1}{12} + 4 \frac{8}{12}$$

1. Выполним действия: 1) $$1 \frac{5}{6} - 1 \frac{7}{12} = \frac{11}{6} - \frac{19}{12} = \frac{22}{12} - \frac{19}{12} = \frac{3}{12} = \frac{1}{4}$$; 2) $$5 \frac{9}{42} - 3 \frac{5}{42} = (5 - 3) + (\frac{9}{42} - \frac{5}{42}) = 2 + \frac{4}{42} = 2 + \frac{2}{21} = 2 \frac{2}{21}$$; 3) $$1 - \frac{27}{43} = \frac{43}{43} - \frac{27}{43} = \frac{16}{43}$$; 4) $$7 \frac{1}{12} + 4 \frac{8}{12} = (7 + 4) + (\frac{1}{12} + \frac{8}{12}) = 11 + \frac{9}{12} = 11 + \frac{3}{4} = 11 \frac{3}{4}$$