\[2^{- 2} + \left( \frac{12}{7} \right)^{- 1} = \frac{1}{2^{2}} + \frac{7}{12} = \frac{1^{\backslash 3}}{4} + \frac{7}{12} =\]
\[= \frac{3 + 7}{12} = \frac{10}{12} = \frac{5}{6}\]