  We solve some forms of non homogeneous differential equations in one and two
dimensions. By expanding the solution into whell-posed closed form-Eisenstein
series the solution itself is quite simple and elementary. Also we consider
Fourier series solutions of linear differential operator equations. In the
third section we study operators which are functions of the Leibnitz
derivative. The last result is the complete solution of a non homogenus
2-degree ODE with linear coeficients. The non homogenous part is an arbirtary
function of $L_2(\bf R\rm)$
