A cell phone company charges a $20 fee every

month and $0.01 for ten

minutes spent talking on

the phone. Write an

equation to model the cost

of a monthly cell phone bill

for the linear function.

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?