[tex] \dfrac{-5}{6}- \dfrac{1}{6}\cdot \Big(\dfrac{2}{3}\Big)^{-2} = \dfrac{-5}{6} -\dfrac{1}{6} \cdot \Big(\dfrac{3}{2}\Big)^{2} = \dfrac{-5}{6}- \dfrac{1}{6}\cdot \dfrac{3^2}{2^2} = \dfrac{-5}{6} - \dfrac{1}{6}\cdot \dfrac{9}{4} = \\ \\ =\dfrac{-5}{6}- \dfrac{9}{24} = \dfrac{-5\cdot 4}{24}- \dfrac{9}{24} = \dfrac{-20-9}{24} = -\dfrac{29}{24}[/tex]
