They sprayed it because Zhu Haokun "mythologized" the book. If you are less than 90 in math, brushing is good. The greatest advantage of this book is its solid foundation.

Zhu Haokun, he gave you the formula above and prepared the corresponding college entrance examination questions for you below, which is very good for students who can't remember the solid formula. The biggest advantage after brushing is that you have gone through all the recipes.