Brandie is trying to decide between two cell phones. one is free with a 2-year contract, but she will have to pay the sales tax of 8% on the original price of $399 and the monthly charge of $10 more (for each month) than she currently pays. the other is on sale for $199, plus 8% sales tax. the monthly charge is the same as she currently pays. over the 2-year contract period, which phone will be the lower cost and by how much?