Over twenty years, it was found that the number of doctors of medicine, md (in thousands), in the united states can be approximated by md=(28,390+693t)/(85-t) where t=0 represents 1980. the number of doctors of osteopathy, do (in thousands), can be approximated by do=(776-12t)/(65-2t) . write an expression for the total number i of doctors of medicine (md) and doctors of osteopathy (do). simplify the result. how many mds did the united states have in 2010? how many mds did the united states have in 2010?