2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78572A general deformation theory of algebras which factorise into two subalgebras is studied. It is shown that the classification of deformations is related to the cohomology of a certain double complex reminiscent of the Gerstenhaber-Schack complex of a bialgebra.12 pages, LaTeX, uses amscd; proof of Theorem 3.1 corrected, new examples and references added; final version to appear in Commun. AlgebraRings and AlgebrasQuantum Algebratext