John currently has enough money to buy 45 books. If the cost of each book was 10 cents less, John could buy 5 more books. How much money does John have to spend on books?

Question

triciaal · Answer

x = cost of book 
amount to spend = 45x 
(x-0.10)(45 + 5) = 45x 
solve for x 
find 45x

mathmate · Answer

An NAR way (No Algebra Required).
John saves $0.10 a book.  How much does he save for 45 books?
This amount buys 5 books, how much would it be for (45+5)=50 books?