The expression given for the charges Ruth paid when she returned the book is:
[tex]\[ 2 + 0.25x \][/tex]
Let's break down the expression to understand the terms involved:
1. The constant term "2": This represents the fixed rental fee for the book, which means Ruth has to pay this amount regardless of when she returns the book.
2. The variable term "0.25x": Here "x" represents the number of days the book was returned late (overdue days). The coefficient "0.25" is multiplied by "x" to compute the total late fee. This implies that for each day the book is overdue, an additional fee of [tex]\(0.25\)[/tex] is added.
Therefore, the second term, "0.25x", specifically represents the late fee per day for the book.
So, the correct answer is:
- The late fee per day for the book