Chapter 4 - Section 4.6 - Complex Fractions and Review of Order of Operations - Exercise Set - Page 284: 30

$2$

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