math formulas are written in a notebook with a pen. The solution of examples and problems in a notebook
ID: 1625570872![复制](//static.hellorf.com/hellorf/_next/images/copy.svg)
![预览](https://hellorfimg.zcool.cn/large/1625570872.jpg)
编辑图片
以图搜图
- 大图:4608 × 2388 像素·39.01 cm × 20.22 cm·300dpi·JPG
- 中图:1000 × 518 像素·35.28 cm × 18.27 cm·72dpi·JPG
- 小图:500 × 259 像素·17.64 cm × 9.14 cm·72dpi·JPG