60,000 people live in a city this year. the birth rate of the city is 14 births per 1,000 people per year. the death rate of the city is 8 deaths per 1,000 people per year. in addition, 100 people move to the city each year and 50 people move out of the city each year. if p is the number of people living in the city at any time (measured in number of years from now), set up a differential equation for p in terms of