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+(-2)-(-3); 6) 2 + (-)-(-2)-

Ответ: 1) 31; 2) -3,6; 3) 0,99; 4) -24,85; 5) 5 11/42; 6) 2 1/48

1. -53 + 61 – 48 + 71 = 8 – 48 + 71 = -40 + 71 = 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. \[5 \frac{3}{7} + (-2 \frac{2}{3}) - (-3 \frac{8}{21}) = \frac{38}{7} - \frac{8}{3} + \frac{71}{21} = \frac{38 \cdot 3}{7 \cdot 3} - \frac{8 \cdot 7}{3 \cdot 7} + \frac{71}{21} = \frac{114}{21} - \frac{56}{21} + \frac{71}{21} = \frac{129}{21} = \frac{43}{7} = 6 \frac{1}{7}\]

6. \[2 \frac{5}{6} + (-3 \frac{7}{8}) - (-2 \frac{1}{12}) - 1 \frac{2}{3} = \frac{17}{6} - \frac{31}{8} + \frac{25}{12} - \frac{5}{3} = \frac{17 \cdot 4}{6 \cdot 4} - \frac{31 \cdot 3}{8 \cdot 3} + \frac{25 \cdot 2}{12 \cdot 2} - \frac{5 \cdot 8}{3 \cdot 8} = \frac{68}{24} - \frac{93}{24} + \frac{50}{24} - \frac{40}{24} = \frac{-15}{24} = - \frac{5}{8}\]

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