Hello to you, I hold a master's degree in applied mathematics from Nantes University shared with the mathematics option of the Ecole Centrale de Nantes, I give private lessons in mathematics at high school level/preparatory cycle for engineering schools/CPGE, it's been 5 years that I carry out this activity and it is always a pleasure to support motivated people and help them to progress and overcome their blocking points. My strategy is simple and effective: Review the course and focus on the concepts that are not well assimilated and rework them in varied and diverse exercises in order to assimilate them, and review examples of classic exams or competitions. I remain at your disposal for any additional information.