2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/77273We show that the action of classical operators associated to the Macdonald polynomials on the basis of Schur functions, S_λ[X(t-1)/(q-1)], can be reduced to addition in λ-rings. This provides explicit formulas for the Macdonald polynomials expanded in this basis as well as in the ordinary Schur basis, S_λ[X], and the monomial basis, m_λ[X].21 pages, TeX, to be published in IMRNCombinatoricsQuantum Algebra05E05text