Lee is sending out 32 invitations. she gives 5 invitations to her mom to give to family member. lee mails a third of the rest write a number expression to describe how many card lee has already mail

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?