A group of 19 students want to see the show at the planetarium. Tickets cost $11 for each student who is a member of the planetariums frequent visitor program and $13 for each student who is not a member. The total cost of the students’ tickets is $209. Let x represent the number of students in the group who are members of the frequent visitor program. Write an expression in terms of x for the number of students in the group who are not members.