<h3>
Answer: Choice A</h3>
The set of all even integers greater than or equal to 50 and less than or equal to 510
In other words, 
where E is an even integer.
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Explanation:
The domain is the set of allowed inputs, while the range is the set of allowed outputs. For now, let's focus on the domain.
In this case, the domain is the set of integers between 0 and 230. We're dealing with the set {0,1,2,..., 229, 230} to represent the possible number of people who bought the video.
Let's plug in the smallest item from the domain (v = 0).
E = 50+2v
E = 50+2*0
E = 50+0
E = 50
This matches with the fact Roger gets paid $50 even if he didn't sell anything. This is the flat up front fee he got.
Now let's plug in the largest value for v (230).
E = 50+2v
E = 50+2*230
E = 50+460
E = 510
This tells us that $510 is the most Roger can get from the audience of 230 people. This is assuming that each person buys only one copy.
So we can see that the range of E values spans from $0 to $510.
Furthermore, notice that 2 can be factored from 50+2v to get 2(25+v). This shows that the expression 50+2v is always even. Therefore, we must clarify that we're dealing with the set of even numbers between 0 and 510
In symbolic form, we'd say 
where E is an even integer.
In roster form, the range of possible E values is {0, 2, 4, ..., 506, 508, 510}.
