An air traffic controller is tracking two planes. To start, Plane A was at an altitude of 820 meters, and Plane B was at an altitude of 1234 meters. Plane A is losing altitude at 15 meters per second, and Plane B is losing altitude at 24 meters per second.

Let x be the number of seconds that have passed.

For each plane, write an expression for the altitude of the plane after x seconds.