3-16 Each of these extreme value problems has a solution with both a maximum value and a minimum value. Use Lagrange multipliers to find the extreme values of the function subject to the given constraint. 6. f(x,y) = xe ", x2 + y2 = 2 27-29 Find the extreme values of f on the region described by the inequality. 28. f(x, y) = 2x + 3y - 4x - 5, x + y 16 30-33 Find the extreme values of f subject to both constraints. 30. f(x, y, z) = z; x + y = z, x + y + z = 24 56. Find the maximum and minimum volumes of a rectangular box whose surface area is 1500 cm and whose total edge length is 200 cm.