-86 + (-46) = -86 - 46 = -132
-2.4 + (-5.5) = -2.4 - 5.5 = -7.9
-0.2 + (-6.1) = -0.2 - 6.1 = -6.3
-8.5 + (-6.19) = -8.5 - 6.19 = -14.69
-715 + (-408) = -715 - 408 = -1123
-6.12 + (-7.8) = -6.12 - 7.8 = -13.92
-4.3 + (-6.57) = -4.3 - 6.57 = -10.87
-60 + (-780) + 60 = -60 - 780 + 60 = -780
-88 + (-17) + (-23) + (-12) = -88 - 17 - 23 - 12 = -140
\[ \left(-\frac{5}{7}\right) + 3 \frac{5}{7} = -\frac{5}{7} + \frac{26}{7} = \frac{26 - 5}{7} = \frac{21}{7} = 3 \]
\[ 1 - \frac{5}{8} = \frac{8}{8} - \frac{5}{8} = \frac{3}{8} \]
\[ 3 \frac{3}{10} - 1 \frac{7}{15} = \frac{33}{10} - \frac{22}{15} = \frac{33 \cdot 3}{10 \cdot 3} - \frac{22 \cdot 2}{15 \cdot 2} = \frac{99}{30} - \frac{44}{30} = \frac{55}{30} = \frac{11}{6} = 1 \frac{5}{6} \]
\[ 10 - 1 \frac{1}{9} = \frac{10}{1} - \frac{10}{9} = \frac{10 \cdot 9}{1 \cdot 9} - \frac{10}{9} = \frac{90}{9} - \frac{10}{9} = \frac{80}{9} = 8 \frac{8}{9} \]
\[ 7 \frac{5}{18} - 1 \frac{7}{12} = \frac{131}{18} - \frac{19}{12} = \frac{131 \cdot 2}{18 \cdot 2} - \frac{19 \cdot 3}{12 \cdot 3} = \frac{262}{36} - \frac{57}{36} = \frac{205}{36} = 5 \frac{25}{36} \]
\[ 9 \frac{5}{6} - 2 \frac{3}{4} = \frac{59}{6} - \frac{11}{4} = \frac{59 \cdot 2}{6 \cdot 2} - \frac{11 \cdot 3}{4 \cdot 3} = \frac{118}{12} - \frac{33}{12} = \frac{85}{12} = 7 \frac{1}{12} \]
\[ 5 \frac{3}{24} - 1 \frac{1}{21} = \frac{123}{24} - \frac{22}{21} = \frac{123 \cdot 7}{24 \cdot 7} - \frac{22 \cdot 8}{21 \cdot 8} = \frac{861}{168} - \frac{176}{168} = \frac{685}{168} = 4 \frac{13}{168} \]
Ответ: Все вычисления выполнены!