By which conversion factor can 800 meters be multiplied to change it to mile

Can someone pls ! pls answer all. no explanation needed..

What is the value of x in the following equation. -x ^3/2 = -27

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?