The last question is 75%, 193 ≥h≤ 8/3, y=a(x-6)? +h, bring a (0 0,2) into the function and get a=(2-h)÷36 (that is, h is used to represent a). If the ball can cross the net, then when x=9, y≥2.43 and h≥ 75, 193? If the ball won't be out of bounds, then when y=0, X≤ 18 and H≤8/3.

The picture is a little ugly, don't take it amiss. .....