Step 1 :Nancy has \(x\) books, Braveen has \(3x + 5\) books, and Cal has \(2(3x + 5) = 6x + 10\) books.
Step 2 :The total number of books is \(x + (3x + 5) + (6x + 10) = 10x + 15\).
Step 3 :\(\boxed{10x + 15 = 245}\) is the equation that represents the total number of books for all three people.