Final answer:
The correct option is Option 2: Total Cost = 5b - 7.
Step-by-step explanation:
The correct option is Option 2: Total Cost = 5b - 7.
To find the total cost of the books after the discount, we can subtract the discount from the total purchase amount. In this case, Leila spent a total of $58 after a discount of $7 off her total purchase. So the equation becomes: Total Cost = 58 - 7 = 51.
Since each book costs $5, we can represent the number of books as 'b'. Therefore, the equation for the total cost becomes:
Total Cost = 5b - 7.