Please help me I don’t know the answer and my test I due in a Hour

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

Bradley hikes 12 miles in 3 hours. in relation to bradley’s hike, which statement describes the expression

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?