Your anwser for letter X is 2
Answer:

Step-by-step explanation:
Given
Equation: 
Required
Determine the equation of Point: (5,4)
First, we need to determine the slope of 
The general form of an equation is 
Where m represents the slope;
Hence; 
Since the equation and the point are parallel. then they have the same slope (m).

Next, is to determine the equation of the point, using the following formula:

Where

So, the equation becomes

Cross Multiply

Open Bracket

Make y the subject of formula


Hence, the equation is 
There is no rate of change.
x=8 and x=13 are horizontal lines going to infinity and negative infinity, its valid for all reals on those 2 lines.
I'm guessing you left out some information on what kind of interpretation you want of these straight lines.