4. Выполните действия: 1) 3,8 + (-4,4); 2) -9,4 + 9,4; 3) 7,6 - (-3,7); 4) -2\(\frac{3}{10}\) + (-3\(\frac{1}{8}\)).

Решение:

1. \(3.8 + (-4.4) = 3.8 - 4.4 = -0.6\)
2. \(-9.4 + 9.4 = 0\)
3. \(7.6 - (-3.7) = 7.6 + 3.7 = 11.3\)
4. \(-2\frac{3}{10} + (-3\frac{1}{8}) = -\frac{23}{10} - \frac{25}{8} = -\frac{23 \times 4}{40} - \frac{25 \times 5}{40} = -\frac{92}{40} - \frac{125}{40} = -\frac{92 + 125}{40} = -\frac{217}{40} = -5\frac{17}{40}\)

Ответ: 1) -0.6; 2) 0; 3) 11.3; 4) -5\(\frac{17}{40}\)