APPENDIX B - Coordinate Geometry and Lines - B Exercises - Page A 16: 47

The region includes all the points between the vertical lines $x = -2$ and $x = 2$, as well as the points on these vertical lines.

$\{(x,y)\vert~\vert x \vert \leq 2~\}$ The region includes all the points where $-2 \leq x \leq 2$ Thus, the region includes all the points between the vertical lines $x = -2$ and $x = 2$, as well as the points on these vertical lines.