PreCalculus
posted by Caroline .
State the domain and range of the relation y = 2x + 3
My answer:
y= 2x+3
y= 2(1)+3=5
domain: 1
range: 5
This is how my book showed me how to do it. I just wanted to make sure I did it right. If not could you please give me an example?

Why are you subbing in x = 1 ?
Did you omit some part of the question?
If y = 2x + 3
you have a straight line, which would go on forever,
so the domain is the set of real numbers
and the range is the set of real numbers.
I am sure you are misreading what the book does, perhaps there were some limitations placed on the length of the line ? 
What they did in their example is substitute x with one. I wasn't exactly sure why they were doing that so I came on here in hopes that someone could better explain it. Thank you!