The profit p in dollars of selling x widgets and y gadgets is given by the function p(x, y)=7x+6y. Which corner point of the shaded region will maximize the profit?

This size running track is usually called a 400 meter track. however if a person ran as close to the inside as possible on the track they would run less than 400 meters in one lap. how far away from the inside border would someone have to run to make one lap equal exactly 400 meters