Answer:
x + 10
Step-by-step explanation:

No, because you would have to simplify like terms. Which the simplest form would be
5x-4
1/6 of a mi - 1 day, 2/6 of a mi- 2 days, 3/6 of a mi- 3 days, 4/6 of a mi- 4 days, 5/6 of a mile - 5 days, 1 mile - 6 days, 1 1/6 mi - 7 days, 1 2/6 mi - 8 days , so on & so forth, do you understand ?
The domain is all of the x values