please finish the following questions

If z = 5x2 + y2 and (x, y) changes from (1, 2) to (0.95, 1.9), compare the values of Az and dz. (Round your answers to four decimal places.) dz = Az = Need Help? Read It Watch It If z = x2 - xy + 9y2 and (x, y) changes from (1, -1) to (1.04, -0.95), compare the values of Az and dz. (Round your answers to four decimal places.) 73% dz = + 2K/S AZ = Need Help? Read It Use differentials to estimate the amount of metal in a closed cylindrical can that is 22 cm high and 4 cm in diameter if the metal in the top and the bottom is 0.1 cm thick and the metal in the sides is 0.05 cm thick. (Round your answer to two decimal places.) cm 3 Need Help? Read It