Respuesta :

The rocket will be 160 feet high after 3 seconds

Explanation:

height = -16t² + 90t + 34

at time = 3 secs

we replace t with 3 secs in the formula above:

height = -16(3)² + 90(3) + 34

height = -16(9) + 270 + 34

Multiplication of same sign gives positive number. Multiplication of opposite signs give negative number.

height = -144 + 270 + 34

height = 160

The rocket will be 160 feet high after 3 seconds