Answer:
17 seconds
Explanation:
h(t) represents height, we want to know when the ball will return to a height of 28 feet. So our equation is..
28 = -2t² + 34t + 28
Now solve for t...
0 = -2t² + 34t (subtract 28 from both sides)
0 = t² - 17t (divide both sides by -2)
0 = t(t - 17) (factor out a t)
So
t = 0
or
t - 17 = 0
t = 17
0 seconds is the initial height. At 17 seconds, the ball will return to that height
i hope this work for you