An onject is. launched from platform. Its height (in meters) x seconds after the launch is modeled by h (x) = -5 (x+1) (*-9) How many seconds after launch will the object hit the ground

9 seconds

Step-by-step explanation:

When the object is on the ground it's height = 0

Equate h (x) = 0, hence

- 5 (x + 1) (x - 9) = 0

equate each factor to zero and solve for x

x + 1 = 0 ⇒ x = - 1

x - 9 = 0 ⇒ x = 9

x > 0 hence x = 9

The object hits the ground 9 seconds after being launched