1. Recite the formula, but not by rote. You should remember in different ways, but each method has its own way.

2. Ask some patient people how to do the problem.

3. Learn from scratch and study hard. (PS: If you really can't, you can learn basic mathematics from primary school! )

If it still doesn't work, just look at the examples and write the exercises.

If you still can't learn, I can't help you. Because of my study method, you may not: occasionally listen carefully and turn over the exercises after class. If not, ask the good students in the class. Do your homework quickly (but carefully). After finishing my homework, I began to play games on the computer. And when you encounter questions that you really don't understand, it will take a long time (but at least before the exam! ), the problem will be understood naturally. So my grades have always been above average in my class.