Answer
$(-\infty,-1]\cup[0,\infty)$
Work Step by Step
$|2x+1|\geq 1$ (Use the property $|x|\geq a$ iff $x\leq -a$ or $x\geq a$)
$2x+1\leq -1$ or $2x+1\geq 1$ (Substract with 1)
$2x\leq -2$ or $2x\geq 0$ (Divide by 2)
$x\leq -1$ or $x\geq 0$
The solution is $(-\infty,-1]\cup [0,\infty)$.
