Answer:
• (a)It costs $77.50 to buy five tickets.
,
• (b)You can by 8 tickets with $130.
Explanation:
The cost (in dollars) of buying x tickets to the orchestra is given by the formula:

(a)When the number of tickets, x=5

It costs $77.50 to buy five tickets.
(b)When the cost, C(x)=$130

You can by 8 tickets with $130.