Using a fixed-point method, we establish the generalized Hyers-Ulam stability of a general mixed additive-cubic equation: f(kx + y) + f(kx - y) = kf(x + y) + kf(x - y) + 2f(kx) - 2kf(x) in Banach modules over a unital Banach algebra.
In this paper, we establish a general solution and the generalized Hyers-Ulam-Rassias stability of the following general mixed additive-cubic functional equation