TANG, Minh Dung; LE , Nguyen Hoang Oanh. ENHANCING MATHEMATICAL PROBLEM-SOLVING COMPETENCY OF NINTH-GRADE STUDENTS THROUGH STAIRCASE SLOPE ANALYSIS. Ho Chi Minh City University of Education Journal of Science, [S. l.], v. 23, n. 9, 2026. DOI: 10.54607/hcmue.js.23.9.5481(2026). Disponível em: https://journal.hcmue.edu.vn/index.php/hcmuejos/article/view/5481. Acesso em: 10 oct. 2026.