181. Найдите значение выражения: 1)-53 + 61 – 48 + 71; 2) 3,17 – 5,9 – 0,87; 3)-0,96 + (-5,37) – (-1,02) + 6,3; 4)-19,23 – 15,88 – (-21,34) + (-11,08); 5) 5\frac{5}{7}+(-2\frac{2}{3})-(-3\frac{8}{21}); 6) 2\frac{5}{6}+(-3\frac{7}{8})-(-2\frac{1}{12})-1\frac{2}{3}.

Ответ: 1) 31; 2) -3,6; 3) 0,99; 4) -24,85; 5) 6 4/7; 6) -1 3/8

1. -53 + 61 – 48 + 71 = 8 + 23 = 31
2. 3,17 – 5,9 – 0,87 = -2,73 – 0,87 = -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 + 10,26 = -24,85
5. \[5\frac{5}{7} + (-2\frac{2}{3}) - (-3\frac{8}{21}) = \frac{40}{7} - \frac{8}{3} + \frac{71}{21} = \frac{40 \cdot 3}{7 \cdot 3} - \frac{8 \cdot 7}{3 \cdot 7} + \frac{71}{21} = \frac{120}{21} - \frac{56}{21} + \frac{71}{21} = \frac{120 - 56 + 71}{21} = \frac{135}{21} = \frac{45}{7} = 6\frac{3}{7} = 6\frac{3}{7}\]
6. \[2\frac{5}{6} + (-3\frac{7}{8}) - (-2\frac{1}{12}) - 1\frac{2}{3} = \frac{17}{6} - \frac{31}{8} + \frac{25}{12} - \frac{5}{3} = \frac{17 \cdot 4}{6 \cdot 4} - \frac{31 \cdot 3}{8 \cdot 3} + \frac{25 \cdot 2}{12 \cdot 2} - \frac{5 \cdot 8}{3 \cdot 8} = \frac{68}{24} - \frac{93}{24} + \frac{50}{24} - \frac{40}{24} = \frac{68 - 93 + 50 - 40}{24} = \frac{-15}{24} = -\frac{5}{8} = -\frac{5}{8}\]

Ответ: 1) 31; 2) -3,6; 3) 0,99; 4) -24,85; 5) 6 4/7; 6) -1 3/8