A = y(9 + 3x) factor y out of 9y+3yx, then devided both sides by (9+3x)
A/(9+3x) = y

The ball reaches its maximum height after 3.5 seconds, and the maximum height is 61.025 meters.
Your answer would be -15.41. If you ever need any other kind of help, just ask me.
SohCahToa
Heard of it?
Sine- opposite over hypotenuse
Cosine-adjacent over hypotenuse
Tangent- opposite over adjacent
Answer: 17.5%
To convert from decimal to percent, just multiply the decimal value by 100. In this example we have: 0.175 × 100 = 17.5% (answer).
➥ The ease way:
1) Move the decimal point two places to the right: 0.175 → 1.75 → 17.5.
2) Add a % sign: 17.5%
Answer: 17.5%