Solve the following linear programming problem.
Maximize: z equals 5x plus 6y
subject to: 7x plus 4y less than or equals 28
10x plus y less than or equals 28
x greater than or equals 0, y greater than or equals 0

An airplane is flying at an elevation of 5150 ft, directly above a straight highway. two motorists are driving cars on the highway on opposite sides of the plane, and the angle of depression to one car is 35 ̊ and to the other is 52 ̊. how far apart are the cars?