A wireless carrier offers the following plans that a person is considering. The Family Plan: $70 monthly fee, unlimited talk and text on up to 5 lines, and data charges of $50 for each device for up to 2 GB of data per device. The Mobile Share Plan: $90 monthly fee for up to 10 devices, unlimited talk and text for all the lines, and data charges of $35 for each device up to a shared total of 10 GB of data. Find the model of the total cost of the Family Plan in dollars. Use P for the number of devices that need data plans as part of their cost.