Chapter 9 - Section 9.8 - Exponential and Logarithmic Equations and Problem Solving - Exercise Set - Page 591: 64

$-\dfrac{5}{6}$

Using the given values of the variables ($x=-2,$ $y=0,$ and $z=3$), the given expression, $ \dfrac{x^3-2y+z}{2z} ,$ evaluates to \begin{array}{l}\require{cancel} \dfrac{(-2)^3-2(0)+3}{2(3)} \\\\= \dfrac{-8-0+3}{6} \\\\= \dfrac{-5}{6} \\\\= -\dfrac{5}{6} .\end{array}