The sum of two numbers is 38 and the difference is 16. find each of the numbers.

Let's say the smaller number is x, and the bigger number is x + 16. the sum of them would be x + x + 16 = 38. subtract 16 from both sides and combine like terms to get 2x = 22. divide both sides to get x = 11. the smaller number (x) is 11, and the bigger number (x+16) is 27.

The shelves will hold 270 books in total