Answer
a.
$z^{4}$
b.
$16a^{20}$
c.
$-54z^{9} $
Work Step by Step
a.
$\frac{z^{2}z^{4}}{z^{3}z^{-1}} = \frac{z^{2+4}}{z^{3-1}} = \frac{z^{6}}{z^{2}} = z^{6-2} = z^{4}$
b.
$(2a^{3}a^{2})^{4} = (2a^{3+2})^{4}= (2a^{5})^{4}= (2^{4}a^{5\times4})=16a^{20}$
c.
$(-3z^{2})^{3}(2z^{3}) = ((-3z^{2})\times(-3z^{2})\times(-3z^{2})) \times (2z^{3}) = (-27z^{2+2+2})\times (2z^{3}) = -27z^{6}\times 2z^{3} = -54z^{6+3} = -54z^{9} $