Answer
$16yz^4$
Work Step by Step
RECALL:
(i) $\dfrac{a^m}{a^n} = a^{m-n}$
(ii) $a^0=1, a\ne0$
Divide the coefficients, and then use the rule(s) above to obtain:
$=16x^{1-1}y^{2-1}z^{6-2}
\\=16x^0y^1z^4
\\=16(1)yz^4
\\=16yz^4$