25 points for who ever me with this

5 seconds

Step-by-step explanation:

h = -16t^2 +64t +80

We want to know when it hits the ground or when h=0

0 = -16t^2 +64t +80

Factor out -16

0 = -16 (t^2 -4t -5)

We can factor inside the parentheses

0 = -16 (t-5) (t+1)

Using the zero product property

t-5 = 0     t+1 =0

t =5   t=-1

Time cannot be negative, so t =5 seconds

step-by-step explanation:

see if this :

207/8 is the right