It says "No more than 8 books are in your bag". Here "Not more than" a specific number would be a set of all values that are "less than or equal" to given number.
So let's consider 'n' represents the number of books in the bag and we know this number can not be a negative value i.e. n is "greater than or equal" to 0.
Also n is "less than or equal" to 8 as given in the question.
Hence, the inequality would be 0 ≤ n ≤ 8.