Campanilla, Norveen. “Integrating Variable to Enhance Problem-Solving Skills of Grade 7 Students in Linear Equations and Inequalities”. International Multidisciplinary Journal of Research for Innovation, Sustainability, and Excellence (IMJRISE), vol. 1, no. 12, Dec. 2024, pp. 190-7, https://risejournals.org/index.php/imjrise/article/view/893.