F(x)=-5t^2+20t+60
Divide everything by -5
f(x)=t^2-4t-12
(t-6)(t+2)
Set it up to zero
t-6=0. t+2=0
t=6. t=-2
Since you can’t have negative seconds, the answer is 6 seconds
Solution: We are given:
The area covered by five great lakes in United States
square miles.
The area covered by the smallest of the great lakes, Lake Ontario
square miles.
The fraction of the area of Ontario lake to the total area of all the great lakes is:


Therefore, the simplest form of fraction is 

X=13 . hope this helps you out
Answer:
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