Solve $\lvert 2x + 1 \rvert \ge 5$.

Explanation

1. 01

   $\lvert u \rvert \ge 5$ means $u \le -5$ or $u \ge 5$.

2. 02

   $2x + 1 \le -5$ gives $x \le -3$; $2x + 1 \ge 5$ gives $x \ge 2$.