176. Вычислите: 1) -43 + (-60) + 18 + 36 + (-19); 2) -2,43 + 6,31 + (-3,21) + 0,49 + 4,87; 3) 19/42 + 9/16 + (-11/42) + 5/16

176. Решение: 1) \(-43 + (-60) + 18 + 36 + (-19) = -43 - 60 + 18 + 36 - 19 = -103 + 54 - 19 = -49 - 19 = -68\) 2) \(-2.43 + 6.31 + (-3.21) + 0.49 + 4.87 = -2.43 + 6.31 - 3.21 + 0.49 + 4.87 = (-2.43 - 3.21) + (6.31 + 0.49 + 4.87) = -5.64 + 11.67 = 6.03\) 3) \(\frac{19}{42} + \frac{9}{16} + (-\frac{11}{42}) + \frac{5}{16} = (\frac{19}{42} - \frac{11}{42}) + (\frac{9}{16} + \frac{5}{16}) = \frac{8}{42} + \frac{14}{16} = \frac{4}{21} + \frac{7}{8} = \frac{32}{168} + \frac{147}{168} = \frac{179}{168} = 1\frac{11}{168}\)