Chapter 3 - Solving Inequalities - 3-2 Solving Inequalities Using Addition or Subtraction - Practice and Problem-Solving Exercises - Page 174: 22

$z\leq8$

$z-12 \leq -4$ : add 12 to both sides $z-12+12\leq -4+12$ : simplify $z\leq 8$ Verify that 8 is a solution at the endpoint. $8-12\overset?= -4$ $-4=-4\checkmark$ Verify that a number less than 8 is a solution. $6-12\overset?\leq -4$ $-6\leq -4\checkmark$