The value of a house in 2015 was 400000. its value has been doubling each decade. 1. if v is the value of the home, in dollars, write an equation for v in terms of d, the number of decades since 2015.
2. What is v when d = -1? What does this value mean.
3. What is v when d = -3? What does this value mean.

Asales representative from a local radio station is trying to convince the owner of a small fitness club to advertise on her station. the representative says that if the owner begins advertising on the station today, the club's total number of members will grow exponentially each month. she uses the given expression to model the number of club members, in hundreds, after advertising for t months.