What is the common difference between the terms in the following sequence?

{17,11,5,−1,−7...}

Let w=23 . what is the value of w + 45 ?

The perimeter of a movie screen is 54 meters. the screen is 18 meters wide. how tall is it?

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?