Answer:
each book saves $295.6875
Explanation:
Let the number of book be n
Total cost = 750 + (n-1)*25
For 100 books
cost = 750 + 99*25 = $3225
each book costs = $322.5
For 400 books
cost = 750 + 399*25 = $10725
each book costs = $26.8125
each book saves $295.6875