It says only 20 points so I'm not helping
1°, because -15° + (2° × 8 hours) = 1°
When the ball hits the ground, the height is 0.
0 = 100 - 16t²
0 = (10 - 4t)(10 + 4t)
0 = 10 - 4t or 0 = 10 + 4t
4t = 10 or -4t = 10
t =
or t = 
Time cannot be negative (unless you have a time machine) so disregard 
Answer: t =
= 2.5 seconds
Answer: x =42°
The angles are equal
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