Sengun, MerveTunc, Cemil2025-05-102025-05-1020231932-9466https://hdl.handle.net/20.500.14720/16534In this study, we pay attention to a functional differential equation (FDE) of first order including N-variable delays. We construct new sufficient conditions in relation to the Hyers-Ulam stability (HUS) and the generalized Hyers-Ulam-Rassias stability (GHURS) of the FDE of first order including N-variable delays. By using Banach contraction principle (BCP), Picard operator and Gronwall's lemma, we confirm two new theorems with regard to the HUS and the GHURS. The results of this study are new, they extend and improve some earlier results of the HUS and the GHURS.eninfo:eu-repo/semantics/closedAccessHusGeneralized HursFde With DelayFixed PointBanach Contraction PrinciplePicard OperatorNew Results of Ulam Stabilities of Functional Differential Equations of First Oder Including Multiple RetardationsArticle182N/AN/AWOS:001133097600004