<span>68=-16t2+64t+8
16t2-64t+60=0
4t2-16t+15=0
(2t-5)(2t-3)=0
t=5/2 or 3/2
The object is at 68 feet after 3/2 secs, and returns to 68 feet after another second..</span>
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You want to find the time (x) when the distance from desitnation is 0:
d = 0,
d(x) = 1375 - 110x
0 = 1375 - 110x
110x = 1375
x = 1375/110
<u>x = 12.5 hrs</u>