Answer:
[tex]\huge\boxed{8^{-2}=\dfrac{1}{64}}[/tex]
Step-by-step explanation:
[tex]a^{-n}=\dfrac{1}{a^n}\Rightarrow 8^{-2}=\dfrac{1}{8^2}=\dfrac{1}{8\cdot8}=\dfrac{1}{64}[/tex]
other examples:
[tex]3^{-1}=\dfrac{1}{3^1}=\dfrac{1}{3}\\\\4^{-3}=\dfrac{1}{4^3}=\dfrac{1}{4\cdot4\cdot4}=\dfrac{1}{64}\\\\\left(\dfrac{1}{3}\right)^{-2}=3^2=3\cdot3=9\\\\\left(\dfrac{2}{5}\right)^{-3}=\left(\dfrac{5}{2}\right)^3=\dfrac{5^3}{2^3}=\dfrac{125}{8}[/tex]
