Achild throws a water balloon down out of a window . substitute 0 for h into the equation h=-16t^2 - 10t+6 to determine how many seconds it takes for the water balloon to reach the ground

t = 3/8 seconds

Step-by-step explanation:

h=-16t^2 - 10t+6

h= 0 when it hits the ground

0=-16t^2 - 10t+6

factor out a -2

0= -2(8t^2 +5t -3)

divide by -2

0 = (8t^2 +5t -3)

factor

0=(8t-3) (t+1)

using the zero product property

8t-3 = 0    t+1 =0

8t = 3         t= -1

t = 3/8     t= -1

t cannot be negative  ( no negative time)

t = 3/8 seconds

answer: .75 km

step-by-step explanation:

m∠a is 90°

m∠b is 40°