Chapter 4 - Section 4.6 - Complex Fractions and Review of Order of Operations - Exercise Set - Page 284: 31

$-\frac{2}{5}$

When $x=-\frac{1}{3}$ and $z=\frac{5}{6}$: $\frac{x}{z}$ $=\frac{(-\frac{1}{3})}{(\frac{5}{6})}$ $=(-\frac{1}{3})\div(\frac{5}{6})$ $=-(\frac{1}{3}\div\frac{5}{6})$ $=-(\frac{1}{3}\times\frac{6}{5})$ $=-(\frac{1}{1}\times\frac{2}{5})$ $=-\frac{2}{5}$