2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/123410Let Cox(S) be the homogeneous coordinate ring of the blow-up S of P^2 in r general points, i.e., a smooth Del Pezzo surface of degree 9-r. We prove that for r=6 and 7, Proj(Cox(S)) can be embedded into G/P, where G is an algebraic group with root system given by the primitive Picard lattice of S and P is a certain maximal parabolic subgroup in G.15 pagesAlgebraic Geometry14J26 (Primary) 14M15, 14C20 (Secondary)text