b There is a sales tax of 6 5 and a processing fee of 7 for a group of tickets Write the total cost 7 a for a dollars spent on tickets c Evaluate TC x d Find TC 8 and interpret its meaning in the context of this problem Part 1 of 4 a Write a function that represents the cost C x in S for x tickets to Riverdance C x 70x Part 1 4 Part 2 of 4 b There is a sales tax of 6 5 and a processing fee of 7 for a group of tickets Write the total cost T a for a dollars spent on tickets T a