Ben has 12 more autographed baseball cards than kevin. if ben has 27 cards, how many does kevin have?

Solve the system of equations. y= 2x y= x^2 - 15

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?

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years