I WILL GIVE BRANLIEST AND FIVE STAR AND HEART ANDD LOTS OF POINTS
(if answered correctly)

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?

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Mat bought a phone for $100. he has to pay $30 per mouth. if he has paid $640 in total, how many mouth has he had the phone?