Answer:
C
Step-by-step explanation:
50 is the total amount of money spent. The total amount of money spent is the cost of a book * number of books bought. If b is the number of books expected, then b+4 is the number of books bought. You multiply (b+4) by 6.25, which is the cost od an individual book, and that equals the total cost, 50 dollars. This is the equation represneted by C
