а) 8^-1+6^-2 б) 2,4^-1+5^0 в) 1453 - 0,1^-3 г) 18-(1/5)^-2

Решение:

1. \( 8^{-1} + 6^{-2} = \frac{1}{8} + \frac{1}{6^2} = \frac{1}{8} + \frac{1}{36} = \frac{9}{72} + \frac{2}{72} = \frac{11}{72} \)
2. \( 2,4^{-1} + 5^0 = \frac{1}{2,4} + 1 = \frac{1}{\frac{24}{10}} + 1 = \frac{10}{24} + 1 = \frac{5}{12} + 1 = 1\frac{5}{12} = \frac{17}{12} \)
3. \( 1453 - 0,1^{-3} = 1453 - \left(\frac{1}{10}\right)^{-3} = 1453 - (10)^3 = 1453 - 1000 = 453 \)
4. \( 18 - \left(\frac{1}{5}\right)^{-2} = 18 - (5)^2 = 18 - 25 = -7 \)

Ответ: а) \(\frac{11}{72}\); б) \(\frac{17}{12}\); в) 453; г) -7.