Textbooks purchased from a cram school. There are blue line stains on the front and back covers. (Images 2 and 4) The answers were written in a notebook, so there are several pages with red pencil checks on the incorrect problems. (Image 5) Please note that there are other pages like this. There are writings on the diagrams problems. (Images 6 and 7) There are no other writings besides these. Answer key included (Image 8)