Chapter 1 - Introduction to Algebraic Expressions - 1.8 Exponential Notation and Order of Operations - 1.8 Exercise Set - Page 67: 128

$1$

Substituting $ x $ with $ -7 $, then the given expression, $ [x+2\div3x]\div[x+2\div3x] $, evaluates to \begin{array}{l}\require{cancel} [-7+2\div3(-7)]\div[-7+2\div3(-7)] \\\\= [-7+6(-7)]\div[-7+6(-7)] \\\\= [-7-42]\div[-7-42] \\\\= [-49]\div[-49] \\\\= 1 .\end{array}