equivalent expressions with possitive exponents and smiplify
1. x^-1/3 read x raised to the negative one over 3
2.(5xy)^-5/6
3(1/8)^-1/3
$\displaystyle x^{\frac{-x}{3}}=\frac{1}{x^{\frac{1}{3}}}$
$\displaystyle (5xy)^{\frac{-5}{6}}=\frac{1}{(5^{frac{5}{6}}x^{\frac{5}{6}}y^{\ frac{5}{6}}}$
for the third one note that $\displaystyle \frac{1}{8}=\frac{1}{2^3}=2^{-3}$
therefore $\displaystyle \bigg(\frac{1}{8}\bigg)^{\frac{-1}{3}}=(2^{-3})^{\frac{-1}{3}}=2^{\frac{-1}{3}\cdot{-3}}=2^1=2$