№ 1. Выполните сложение: 1) -17 + 9; 2) -3,5 + 7,3; 3) 15,7 + (-7,3); 4) 6,32 + (-17,6); 5) -8,7 + 8,7; 6) -1 + 0,924; 7) -5/6 + 7/8; 8) 5 3/7 + (-3 4/5); 9) -7 4/9 + 3 5/6.

Решение:

1. \(-17 + 9 = -8\)
2. \(-3,5 + 7,3 = 3,8\)
3. \(15,7 + (-7,3) = 15,7 - 7,3 = 8,4\)
4. \(6,32 + (-17,6) = 6,32 - 17,6 = -11,28\)
5. \(-8,7 + 8,7 = 0\)
6. \(-1 + 0,924 = -0,076\)
7. \(-\frac{5}{6} + \frac{7}{8} = -\frac{5 \cdot 4}{6 \cdot 4} + \frac{7 \cdot 3}{8 \cdot 3} = -\frac{20}{24} + \frac{21}{24} = \frac{1}{24}\)
8. \(5 \frac{3}{7} + (-3 \frac{4}{5}) = \frac{38}{7} - \frac{19}{5} = \frac{38 \cdot 5}{7 \cdot 5} - \frac{19 \cdot 7}{5 \cdot 7} = \frac{190}{35} - \frac{133}{35} = \frac{57}{35} = 1 \frac{22}{35}\)
9. \(-7 \frac{4}{9} + 3 \frac{5}{6} = -\frac{67}{9} + \frac{23}{6} = -\frac{67 \cdot 2}{9 \cdot 2} + \frac{23 \cdot 3}{6 \cdot 3} = -\frac{134}{18} + \frac{69}{18} = -\frac{65}{18} = -3 \frac{11}{18}\)

Ответ: 1) -8; 2) 3,8; 3) 8,4; 4) -11,28; 5) 0; 6) -0,076; 7) 1/24; 8) 1 22/35; 9) -3 11/18.