Trịnh Thị LM. TEACHERS’ DIFFICULTIES IN THE EXPLOITATION AND REINFORCEMENT OF MATHEMATICAL ACTIVITIES FOR STUDENTS IN TEACHING ALGEBRA 10: A PRACTICAL STUDY AT SELECTED HIGH SCHOOLS IN THE PROVINCE. gdql [Internet]. 2026Mar.30 [cited 2026Jul.2];85(3). Available from: https://hdujs.edu.vn/index.php/gdql/article/view/1007