Tickets for the school play cost $7 each. Each member of the cast gets 1 free ticket for a family member. For the run of the play, 210 tickets are collected, including all the free tickets, and the box office makes $1,358 from ticket sales. The equation that models this situation is7(210 – c) = 1,358 where c is the number of cast members. How many cast members are in the play?