Find the absolute maximum and minimum values of the function, subject to the given constraints. k(x,y)= - x

Find the absolute maximum and minimum values of the function, subject to the given constraints. k(x,y)= -x2 -Y2 +6x +6y; 0 sxs4, y-20, and x + y The minimum value of k is a. (Simplify your answer.) The maximum value of k is (Simplify your answer.)