Each sweatshirt cost $20, but we don't know how many sweatshirts someone will buy so we use X, representing the amount of sweatshirts. There is a shipping charge of $4.99, so we have to add that to the cost of the sweatshirts. 20x+4.99. Y is the total cost.
Ken moved 7 to the right which is correct because he needs to get 7º higher, but when he moved 2º to the left that would be a temperature decrease which is is incorrect.
