Martha pays $2000 for materials to make earrings. She makes 10 earrings and sells 7 for $500 and 3 for $200. Write a numerical expression to represent this situation and then find Martha's profit?

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?

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

Apool measures 12.3 feet by 16.6 feet. if the longer wall of the pool has a diagonal of 17.8 feet, what is the volume of the pool? (round to nearest tenth)