how do you work this out 2^(-3)

2^(-3)

\(2^{-3}=\frac{ 1*2^{-3}}{\color{green}{1}}=\frac{ 1}{\color{green}{1*2^3}}=\frac{1}{8}\)

Whatever is raised to a negative power gets swapped to the other side of the fraction line and the negative power becomes a positive power.