31. Найдите значение выражения

31. Найдите значение выражения: 1) $-53 + 61 - 48 + 71 = 8 - 48 + 71 = -40 + 71 = 31$ 2) $3,17 - 5,9 - 0,87 = (3,17 - 0,87) - 5,9 = 2,3 - 5,9 = -3,6$ 3) $-0,96 + (-5,37) - (-1,02) + 6,3 = -0,96 - 5,37 + 1,02 + 6,3 = -6,33 + 7,32 = 0,99$ 4) $-19,23 - 15,88 - (-21,34) + (-11,08) = -19,23 - 15,88 + 21,34 - 11,08 = -35,11 + 21,34 - 11,08 = -13,77 - 11,08 = -24,85$ 5) $5\frac{3}{7} + \left(-2\frac{2}{3}\right) - \left(-3\frac{8}{21}\right) = 5\frac{3}{7} - 2\frac{2}{3} + 3\frac{8}{21} = 5\frac{9}{21} - 2\frac{14}{21} + 3\frac{8}{21} = 4\frac{30}{21} - 2\frac{14}{21} + 3\frac{8}{21} = 2\frac{16}{21} + 3\frac{8}{21} = 5\frac{24}{21} = 6\frac{3}{21} = 6\frac{1}{7}$ 6) $2\frac{5}{6} + \left(-3\frac{7}{8}\right) - \left(-2\frac{1}{12}\right) - 1\frac{2}{3} = 2\frac{5}{6} - 3\frac{7}{8} + 2\frac{1}{12} - 1\frac{2}{3} = 2\frac{20}{24} - 3\frac{21}{24} + 2\frac{2}{24} - 1\frac{16}{24} = (2\frac{20}{24} + 2\frac{2}{24}) - (3\frac{21}{24} + 1\frac{16}{24}) = 4\frac{22}{24} - 4\frac{37}{24} = -\frac{15}{24} = -\frac{5}{8}$