3. Найдите значение выражения:
1) $$-34 + 67 + (-19) + (-44) + 34 = -34 + 67 - 19 - 44 + 34 = 67 - 19 - 44 = 48 - 44 = 4$$
2) $$6 + (-7) - (-15) - (-6) - 30 = 6 - 7 + 15 + 6 - 30 = 6 - 7 + 21 - 30 = -1 + 21 - 30 = 20 - 30 = -10$$
3) $$3 \frac{1}{6} + (-2 \frac{5}{9}) - (-1 \frac{7}{12}) = 3 \frac{1}{6} - 2 \frac{5}{9} + 1 \frac{7}{12} = 3 \frac{6}{36} - 2 \frac{20}{36} + 1 \frac{21}{36} = 3 \frac{6}{36} + 1 \frac{21}{36} - 2 \frac{20}{36} = 4 \frac{27}{36} - 2 \frac{20}{36} = 2 \frac{7}{36}$$