Answer: 
Step-by-step explanation:
What you are trying to do is isolate the variable x. For you to do that you have to first simplify the left side of the equation and then you solve for x.
Answer:

n ≈ 3
Step-by-step explanation:
9n-2<7+20

Answer:
huh?
Step-by-step explanation:
I think it's the second one on the top, because the dotted one is actually inside the bigger one and you can get a clear representation of the sizes.