Atextbook order was shipped in 3 identical boxes, each containing 8 pounds of books, and a fourth box containing 6 pounds of books. if 15 copies of the same textbook were in the boxes, which expression shows how to determine the weight of each textbook? (8 × 3 + 6) ÷ 15 or 8 × 3 + 6 ÷ 15 or (8 × 3) + (6 ÷ 15) or 8 × (3 + 6) ÷ 15