б) $$10^0 - 1,2^{-1} = 1 - (\frac{12}{10})^{-1} = 1 - \frac{10}{12} = 1 - \frac{5}{6} = \frac{6}{6} - \frac{5}{6} = \frac{1}{6}$$
Ответ: $$\frac{1}{6}$$