Greatest common factor of 39 & 14

If you shift the linear parent function, f(x)=x, up 13 units, what is the equation of the new function?

At a sale this week, a desk is being sold for $213. this is a 29% discount from the original price. what is the original price?

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?