Simanjuntak, Nasri, Samuel Juliardi Sinaga, and Adi Suarman Situmorang. “Efektivitas Model Pembelajaran Problem Based Learning (PBL) Terhadap Kemampuan Pemahaman Matematis Siswa Pada Materi Sistem Persamaan Linear Dua Variabel (SPLDV) Kelas VIII SMP Negeri 13 Medan”. Innovative: Journal Of Social Science Research 3, no. 5 (October 27, 2023): 6173–6190. Accessed April 24, 2026. https://j-innovative.org/index.php/Innovative/article/view/5580.