ESTABLISH AN ADDITIVE (s;t)-FUNCTION IN EQUALITIES BY FIXED POINT METHOD AND DIRECT METHOD WITH n-VARIABLES IN BANACH SPACE
In this paper we study to solve the of additive s, t -functional inequality with n-variables and their Hyers-Ulam stability. First are investigated in Banach spaces with a fixed point method and last are investigated in Banach spaces with a direct method.These are the main results of this paper.
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 Corresponding Author: Ly Van An.
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