A graph has oil changes on the x-axis and total cost (dollars) on the y-axis. A line goes through (1, 75) and (2, 90) and another line goes through (1, 30) and (2, 60). A gas station offers two ways to pay for oil changes. Plan 1: Pay $30 per oil change. y = 30x Plan 2: Pay $60 for the first oil change and $15 for every oil change after the first. y = 15x + 60 At how many oil changes will the cost for both plans be equal? oil changes