Answer: y: height, x: time.
Explanation:
The data we have is:
The initial position of Greyson is 75ft above the river.
He needs 1.5 seconds to hit the water, and other 0.5s tho reach the bottom of the river.
Then we have a relationship of height vs time.
The y axis will represent the heigth of Greyson, and the x-axis will represent the time, such that at the time x = 0 seconds, we have y = 75ft