Two factories together have marginal abatement cost equal to MACT = 750 - 6eT, where e1 + e2 = eT. The undesirable pollutant imposes a cost on the residents of society and this is given by the marginal damage cost MD= 4eT. Enter a whole number in each blank. The efficient level of emissions is equal to ________. The total cost of reducing emissions to the efficient level is $_______. The total benefit of reducing emissions to the efficient level is $________. The net benefit of reducing emissions to the efficient level is $___________.