"x" can be any number right? what the graph is saying is that x can be any number on the blue line.
What's important to notice is that the circle at 0 is not colored in. This means x can be everything up to 0... but it cannot be 0. For example, x can be -0.0001 because that is less than 0.
In total, x can be anything less than 0, it just cannot be 0.
