Answer
$z-z^{17/3}$
Work Step by Step
Using the Distributive Property and the properties of radicals, the expression $
z^{2/3}(z^{1/3}-z^5)
$ is equivalent to
\begin{array}{l}
z^{2/3}(z^{1/3})-z^{2/3}(z^5)
\\\\=
z^{\frac{2}{3}+\frac{1}{3}}-z^{\frac{2}{3}+5}
\\\\=
z^{\frac{3}{3}}-z^{\frac{2}{3}+\frac{15}{3}}
\\\\=
z-z^{\frac{17}{3}}
\\\\=
z-z^{17/3}
.\end{array}
