Answer
$$\frac{6y^3}{x^{7}z}$$
Work Step by Step
$(-\frac{1}{3}x^{-5}y^{4}z^{6})(-18x^{-2}y^{-1}z^{-7})$
Recall the product rule: $a^{m}\cdot a^{n} = a^{m+n}$
Thus,
$$(-\frac{1}{3}\cdot -18)(x^{-5-2})(y^{4-1})(z^{6-7})$$
$$=6(x^{-7})(y^{3})(z^{-1})$$
Recall the negative exponent rule: $a^{-n} = \frac{1}{a^n}$
Hence,
$$=\frac{6y^3}{x^{7}z}$$
