Answer:
15000+1250x
Explanation:
Since the initial population is 15,000, we want to know how many people are going to Jonesville each year. Assuming that in 2001 and in 2002, each year adds 1,250 people and that it is constant. The equation is 15000+1250x in which 15,000 represents the initial number and 1250 is the amount of people added each year followed by x which is the number in years.