Answer
$-3z^5+z^2+7z$
Work Step by Step
Removing the grouping symbols and then combining like terms, the given expression, $
(z^5+3z^2+2z)-(4z^5+2z^2-5z)
,$ simplifies to
\begin{array}{l}\require{cancel}
z^5+3z^2+2z-4z^5-2z^2+5z
\\\\=
(z^5-4z^5)+(3z^2-2z^2)+(2z+5z)
\\\\=
-3z^5+z^2+7z
.\end{array}