Răspuns :
[tex]\it Not\breve am\ \ -\dfrac{5}{4}=a,\ iar\ expresia\ devine:\\ \\ a^{-2}:a^{-6}\cdot a^6=a^{-2-(-6)+6}=a^{10} \Rightarrow\ inversul\ este \ \ a^{-10}=\Big(-\dfrac{5}{4}\Big)^{-10}=\\ \\ \\ =\Big(\dfrac{4}{5}\Big)^{10}[/tex]
[tex]\it Not\breve am\ \ -\dfrac{5}{4}=a,\ iar\ expresia\ devine:\\ \\ a^{-2}:a^{-6}\cdot a^6=a^{-2-(-6)+6}=a^{10} \Rightarrow\ inversul\ este \ \ a^{-10}=\Big(-\dfrac{5}{4}\Big)^{-10}=\\ \\ \\ =\Big(\dfrac{4}{5}\Big)^{10}[/tex]