There are 318 fiction books in the class library. tha number of non fiction book is 47 less than double the number of fictions book. about how many non fiction books are there in the class library?

Salutations!

There are 318 fiction books in the class library. The number of non fiction book is 47 less than double the number of fictions book. About how many non fiction books are there in the class library?

Let the number of non fiction books me 'NF'.

Let 'F' be fiction

Double means '2', therefore:

2F - 47 = non fiction (NF)

2(318) - 47 = non fiction 

As you can see brackets indicate multiplication, therefore you will be multiplying 318 and 2

636 - 47 = non fiction (NF)

Subtract 47 from 636

589 = nonfiction (NF)

There are 589 non fiction books in the library. 

Hope I helped (:

Have a great day!

The third question is correct.