A telephone company charges $.35 for the first minute of a phone call and $.15 for each additional minute of the call. Which of the subsequent represents the cost y of a phone call lasting x minutes?
Let x = the total minutes of the call. Therefore, x - 1 = the additional minutes of the call. This choice is correct since in order to compute the cost, the charge is 35 cents plus 15 cents times the number of additional minutes. If y represents the total cost, after that y equals 0.35 plus 0.15 times the quantity x - 1. This translates to y = 0.35 + 0.15(x - 1) or y = 0.15(x - 1) + 0.35.