1.1(3) as a simplified fraction

Which is an equation for the nth terms of the sequence 12,15,18,21

Abcd ≅ klmn ≅ pqrs ≅ wxyz given that information, which figures are reflections of abcd?

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?