You put every inequality into x _ form and this will give you the information on how it looks on a number line
example:
2x+1 </ 3
-1 both sides
2x </2
÷2 both sides
x </1
this inequality resembles #2 numberline
The dot is at 1
The dot is closed not opened
and the line moves to the left meaning x is LESS THAN or equal to (</)