Final answer:
The greatest number of teachers that can receive books equally, given 56 fiction books and 42 nonfiction books, is 14, which is the greatest common divisor of 56 and 42.
Step-by-step explanation:
The school library ordered 56 fiction books and 42 nonfiction books and wants to distribute them equally to the greatest number of teachers. To find the greatest number of teachers that will receive books equally, we need to find the greatest common divisor (GCD) of the two numbers, 56 and 42. The GCD of 56 and 42 is 14. This means the greatest number of teachers that can receive books equally is 14 teachers.