Answer:
c(x) = 1.50 + 1.25x
Explanation:
Oo this is an easy one once you have it figured out!
So we have a flat fee of 1.50 dollars, so we know that is by itself because she could rent it for 100 days and that number would not change. So far our equation looks like this:
c(x) = $1.50
Now, right away after doing that I can tell you it is the top function, but let us figure out the second part first. (all the others affect $1.50 with x somehow, and the third one doesn't account for time at all)
If we want x to represent days she has the movie, and $1.25 is the price, we can put $1.25 and x together to get our second part of the equation, "+ 1.25x" so our final cost function equation looks like this:
c(x) = 1.50 + 1.25x
Resulting in our answer, the first option :D