Let's use the following inequation as an example:

First let's simplify it dividing the inequation by 2:

Now, let's draw a number line, and include the point 3 in it:
We want the values of y that are greater than 3, that is, the numbers to the right of the number 3 in the number line. So we mark the area that corresponds to the values of y that satisfies the inequation:
The number 3 is not part of the answer, because 3 is not greater than 3, so we draw a small empty circle on the number 3. If the number 3 was part of the answer, the circle would be filled.