Simplify the Exponential Expression

[zahariastoianovici]

Why not express 8 as 2^3 and simplify with intial power of -1/3, avoiding the radical

[MrPaulc]

With less complex ones like this, I might calculate it without the minus sign (to get 2), then flip denominator and numerator). i.e. 2/1 becomes 1/2 .