Which shows the following expression after the negative exponents have been eliminated? a^3 b^-2 / ab^-4 , a=/0 , b=/0

I'll give brainliest if you answer right : )

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?

Iam a rectangle. my perimeter is 60 feet. how much are do i cover?