Write a variable expression to describe the rule for the sequence. then find the 100th term in the sequence. –4, 1, 6, 11, 16

a] Explicit formula
–4, 1, 6, 11, 16
from the given sequence:
the common difference is:
d=1-(-4)=5
this implies that the series is an arithmetic series thus it will take the explicit form
an=a+(n-1)d
where:
a=first term
d=common difference
hence
plugging in the values we obtain the explicit formula  for the series is:
an=-4+5(n-1)
simplifying gives us:
an=-4+5n-5
hence
an=5n-9
 

b] The 100th term
Using the formula for the series, the 100th term will be found as follows:
an=5n-9
n=100
hence
a₁₀₀=5(100)-9
=500-9
=491

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.