Suppose that a car rental agency charges a fixed amount per day plus an amount per mile for renting a car. heidi rented a car one day and paid $58 for 190 miles. on another day she rented a car from the same agency and paid $86 for 330 miles. find the linear function f(x) (where x is in miles and f(x) is in dollars) that the agency could use to determine its daily rental charges.