8 1/3-16 root 3

$$8\frac{1}{3}-16\sqrt3\\\\
=\frac{25}{3}-\frac{16\times 3\sqrt3}{3}\\\\
=\frac{25-48\sqrt3}{3}$$

This is the nicest presentation for this question.

I don't quite understand. Do you mean the third root of (8+1/3)-16? If so, then it's not a real number, because roots of negatives are weird that way.