Five notebooks cost $20. at this rate, how much would 4 notebooks cost

each notebook cost 5$ So it equals 20$ 4 notebooks is 15$

Divide 20 by 5 to get the cost of one notebook. Then multiply that by 4 to get the cost of 4 notebooks 

20/5 = 4

4*4 = 16

Letter c i’d say

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.