Hi there!
First, let's solve the inequality:
3n - 6 < 12
3n < 18
n < 6
How we'll graph it:
First, number your line. Then, draw an OPEN circle on the number 6 and draw an arrow that points to the numbers that are GREATER than 6.
Hope this helps!! :)
If there's anything else that I can help you with, please let me know!