Combined boundary value problems for the nonhomogeneous tri-analytic equation

In the present article we present a particular combination of boundary problems for the inhomogeneous tri-analytic equation: the Neumann-(Dirichlet-Neuman) problem and the (Dirichlet-Neumann)-Dirichlet problem. In order to obtain the solution and solvability conditions we use an iteration's process involving those corresponding to equations of lower order.