“…The study of the properties of weighted pseudoinverse matrices and weighted normal pseudosolutions, as well as the construction of methods for solving these and other problems, are devoted to the works of Mitra, Rao, Van Loan, Wang, Galba, Deineka, Sergienko, Ben-Israel, Elden, Wei, Wei, Ward etc. Weighted pseudoinverse matrices and weighted normal pseudosolutions with degenerate weights were studied in [3][4][5]. The existence and uniqueness of weighted pseudoinverse matrices with indefinite and mixed weights, as well as some of their properties, were described in [6][7][8].…”