A closed surface with dimensions a = b = 0.400 m and c = 0.800 m is located as shown in the figure below. The left edge of the closed surface is located at position x = a. The electric field throughout the region is non-uniform and given by E→ = (1.60 + 5.00x2) i N/C, where x is in meters. (a) Calculate the net electric flux leaving the closed surface. (b) What net charge is enclosed by the surface?