OICC Press Fuzzy Optimization and Modeling Journal (FOMJ) 2676-7007 5 4 2024 04 24 Solving Fuzzy LR Interval Linear Systems using Nonlinear Programming 33 43 10.71808/fomj.2024.1190245 EN Khatere Ghorbani-Moghadam Mosaheb Institute of Mathematics‎, ‎Kharazmi University‎, ‎Tehran‎, ‎Iran Reza Ghanbari Faculty of Mathematical Sciences, Ferdowsi University of Mashhad, Mashhad, Iran. Mahnoosh Salari Department of Mathematical Sciences‎, ‎Ferdowsi University of Mashhad‎, ‎Iran Journal Article 2024 04 24 In this paper‎,‏‎ we use the least squares method to solve LR fuzzy interval systems by transforming an interval fuzzy number into two triangular fuzzy numbers. Then, ‎w‎e reduce the distance between the two obtained triangular fuzzy numbers to solve the fuzzy ‎LR‎ interval linear system. Essentially, we convert an LR fuzzy interval linear system into a triangular fuzzy linear system and subsequently solve it using the least squares method introduced ‎in [17, 18].