QUESTION 4 Consider the function f (x.y) =2ry + 4 subject to the constraint x + y = 20- Setup the Lagrange function F (x.y.x) and find F Recall that F , = - g (x,y) -x-y-201 O -x- y+ 20 2xy - 20 QUESTION 5 Consider the function f(x,y)=2xy + 4, subject to the constraint x + y = 20. Set F, = 0, Fy =0, F, =0 and solve for X and y. O x = 10, y= -10 O x = 8, y=-8 O x = 10, y=10 O x =8, y=8 QUESTION 6 Consider the function f(x,y) =2xy + 4, subject to the constraint x + y = 20. What is the maximum value of the function? O 204 0 512 O 256 128