Expression of the Drazin and MP-inverse of partitioned matrix and quotient identity of generalized Schur complement

In this paper we give representations of the Drazin and MP-inverse of a 2×22×2 block matrix and quotient identities for the generalized Schur complement of a partitioned 3×33×3 matrix under conditions different than those used in recent papers on the subject. We present numerical examples to illustrate our results.