Ngoc Giang, N. et al. 2024. INTEGRATING MATHEMATICS AND ECONOMICS WITH THE SUPPORT OF GEOGEBRA SOFTWARE IN TEACHING THE SYSTEM OF FIRST-ORDER INEQUALITIES WITH TWO UNKNOWNS AT THE HIGH SCHOOL LEVEL. HNUE Journal of Science: Journal of Educational Science. 69, 5B (Dec. 2024), 191–200. DOI:https://doi.org/10.18173/2354-1075.2024-0147.