Susan has 5 pounds of flour. she is purchasing more flour. she can purchase up to 5 bags of flour. each bag weighs 20 pounds. susan cannot purchase partial bags. the function that models the number of pounds of flour she has is f(b)=20b+5f(b)=20b+5 , where b is the number of bags of flour she purchases. what is the practical domain of the function? all real numbers all integers from 1 to 5 inclusive {25,45,65,85,105}{25,45,65,85,105} all real numbers from 1 to 5 inclusive