Answer: Our inequality would be

Explanation:
Since we have given that
No more than 5 books are in his backpack.
Let the number of books be 'b'.
Since there should not be more than 5 books.
So, less than or equal sign should be used.
As number of books should be less than or equal to 5.
So, Mathematically, it is expressed as

Hence, our inequality would be
