1) -34 + 67 + (-19) + (-44) + 34 = -34 + 67 - 19 - 44 + 34 = 67 - 19 - 44 = 4
2) 6 + (-7) - (-15) - (-6) - 30 = 6 - 7 + 15 + 6 - 30 = 27 - 37 = -10
3) 3 \frac{1}{6} + (-2 \frac{5}{9}) - (-1 \frac{7}{12}) = \frac{19}{6} - \frac{23}{9} + \frac{19}{12} = \frac{114}{36} - \frac{92}{36} + \frac{57}{36} = \frac{79}{36} = 2 \frac{7}{36}