Since the lowest weight possible is 5lbs (just the barbell and no weights) the lowest point of the range is 5lbs (the y intercept when x = 0)
The highest weight possible is 85lbs since, there is only 8 pairs of weight plates (8 is the input value) and the pairs each weigh 10lbs (the slope of the graph) + 5lbs from the barbell (y-intercept).
Using the function given, if you input 8 as the x value, you get
85 = 10(8) + 5
So the highest value of the range is 85lbs, therefore the range is 5 <= y <= 85.
