Answer:

Step-by-step explanation:
Givens:
is the price of the ticket, after the offer.
is the original price of the ticket, before the offer.
So, knowing what represents the variables, we can write an expression to model this situation. The expression would be:

The difference is modelling the offer, the discount from the coupon, it says that such coupon offers a discount of 70% of the original prices, and that percentage is represented by 0.70, multiplied by
because that variable represents the original price. In addition, we have to subtract, because a discount means lower price, less than the original.
Therefore, the expression is:

In words, with the coupon, people just pay 30% of the original price.