there are websites such as
mathpapa
algebra tiger - favorite
and many more that will give you the CORRECT answer and will give u a step by step explanation on how it was answered
11x + x = 12x
312 / 12 = 26
26 nonfiction
312 - 26 = 286.
He has 26 non fiction books and 286 fiction books.
<span>Hope This Helps You!
</span>Good Luck Studying :)