An object is launched from a platform. It's height is meters is modeled by: h (x) = - 5 (x+1) (x-9) where x represents the time in schools after the launch. How many seconds after launch will the object hit the ground

Answer: 9 seconds

Step-by-step explanation:

When the object hit the ground,

Height h = 0

Therefore,

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

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

Open the bracket

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

0 = - 5x^2 + 45x - 5x + 45

0 = - 5x^2 + 40x + 45

Divide all by - 5

0 = x^2 - 8x - 9

Factorizing the equation gives

(x + 1) (x - 9)

x = - 1 or 9

Since Time can't be negative

Therefore, the time seconds after launch the object will hit the ground is 9 seconds