5. In a book store, the price of a book is $ 9.
The same book costs $ 12 in a super market.
Julie buys (x + 8) books from the book store.
Sandy buys (x + 4) books from the super market.
(a) If they both pay the same amount, write down an equation in
terms of x
(b) Solve your equation to find the number books each has
purchased.