Find the extremum of f(x,y) subject to the given constraint, and state whether it is a maximum or a minimum. f(x,y) = xy; 13x + y = 6 . . . There is a value of located at (x,y) = (Simplify your answers.)Find the extremum of f(x,y) subject to the given constraint, and state whether it is a maximum or a minimum. f( x,y) = 2x2 + y?; 2x+y=6 . . . There is a value of located at (x, y) = 7 (Simplify your answers.)Find the extremum of f(x,y) subject to the given constraint, and state whether it is a maximum or a minimum. f(x,y) = 8 -x2- y"; x+2y=5 . . . There is a value of located at (x,y) = 7. (Simplify your answers.)