a cell phone plan costs $28.90 per month for 400 minutes of talk time. it costs an additional $0.07 per minute for each minute over 400 minutes. to get e-mail access, it costs 10% of the price for 400 minutes of talk time. your bill, which includes e-mail, is the same each month for 8 months. the total cost for all months is $298.56. write and solve an equation to find the number of minutes of talk time you use each month.