Chapter Appendices - Section A.1 - Real Numbers and the Real Line - Exercises - Page AP-6: 3

$x \lt -2$

Multiply the inequality with $-\displaystyle \frac{1}{2}\quad$ (to isolate x). Apply rule 4 from the table "Rules for Inequalities", by which multiplying with a negative number, the inequality changes direction: $x \lt -2$ This inequality describes an open interval, $x\in(-\infty,-2)$ See table: "Types of intervals."