Answer
4a. $x\lt-3$
4b. $x\geq0$
Work Step by Step
4a. The circle is open, so the line goes indefinitely to the left, and starts from -3. This means that the sign does not need a line under it, and it is a less than sign.
4b. The circle is closed, so the line goes indefinitely to the right, and starts from 0. This means that the sign needs a line under it, and it is a greater than sign.
