Given an arithmetic sequence in the table below, create the explicit formula and list any restrictions to the domain.

So the numbers are increasing by adding 7.

B is the correct answer because you add 7 from 40

a(n) = 40 + 7(n - 1)

for example... 
If you want 5th term,
a(5) = 40 + 7(5 - 1)
40 + 28 = 68.

In all honesty, there really is no “work” per say to show. mainly it’s just using the process of elimination. the question is asking which domain(s) would be the most appropriate for the function c(n). n is the number of observed vehicles so right away, 1, 2, and 3 can be eliminated.why? 1, 2 start in the negatives and therefore it is impossible to observe negative cars. so, #4 would be the best answer to the given problem.