Amy is riding a cable car to a lodge. Her distance from the lodge is recorded from the start of the ride to the end.
Let y be the distance (in meters) from the lodge and let x be the amount of time (in seconds) since the ride started. The equation y=-5x+600 models y as a function of x . As shown in the graph below, this model is accurate only from the start of the ride until the end. (The endpoints of the graph show when the ride starts and ends.)
Distance from the lodge (meters)
y1002003004005006007008009001000x204060801001201401601802000
Amount of time (seconds)
x20406080100120140160180200
Based on the equation y = -5x + 600, the time (in seconds) when Amy reaches the lodge is 120 seconds.