The population density of a city is given by P(x, y) = - 20x - 25y + 200x + 250y + 170, where x and

The population density of a city is given by P(x, y) = - 20x² - 25y² + 200x + 250y + 170, where x and y are miles from the southwest corner of the city limits and P is the number of people per square mile Find the maximum population density, and specify where it occurs.The maximum density is___ people per square mile at (x ,y)=___