Answer :
Final answer:
The correct equation to find John's elevation relative to his starting point after riding down the hill is Elevation = 173 - x, which accounts for the loss in elevation as he moves downhill. The correct answer is option a.
Explanation:
The equation that can be used to find John's elevation in feet relative to his starting point after he rides his bicycle 173 feet down the hill into a valley is Elevation = 173 - x, where x represents the change in elevation from the top of the hill to the valley. This is because as John travels down the hill, he loses elevation with respect to his starting point at the top of the hill. Letter a, Elevation = 173 - x, would correctly represent John's elevation after the descent if we assume that the starting elevation at the top of the hill is 0 feet.
Therefore, as John descends, the elevation decreases by the distance x traveled down the hill.
