20. Karen used a birthday check her mother gave her to start a savings account. She plans to save $25 per month as well. After 8 months, Karen has $250. Write and solve a linear equation to find the original check
amount from Karen's mother.

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.