638.453 + (400•30 - 3.921)= 638.453 + (12000 - 3.921)= 638.453 + 11996.079= 12634.532
Therefore, 638.453 + (400•30 - 3.921) = 12634.532
638.453 + (400•30 - 3.921)
= 638.453 + (12000 - 3.921)
= 638.453 + 11996.079
= 12634.532
Therefore, 638.453 + (400•30 - 3.921) = 12634.532