Plane A is descending toward the local airport, and plane B is ascending from the same airport. Plane A is descending at a rate of 2,500 feet per minute. Plane B is ascending at a rate of 4,000 feet per minute. If plane A is currently at an altitude of 14,000 feet and plane B is at an altitude of 1,000 feet, how long will it take them to be at the same altitude? The equation representing plane A’s descent is y = -2,500x + 14,000. The equation representing plane B’s ascent is y = 4,000x + 1,000. In both equations, y represents altitude and x represents time in minutes.