Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682210120191101Hermitian solutions to the system of operator equations $T_iX=U_i$139152405910.22075/ijnaa.2017.1475.1378ENS.MansourVaezpourAmirkabir University of Technology (Tehran Polytechnic), Tehran, IrannullZahraBakhtiariDepartment of Mathematics, Payame Nour University, Tehran, IranJournal Article20171228In this article, we consider the system of operator equations $T_iX=U_i$ for $i=1,2,...,n$ and give necessary and sufficient conditions for the existence of common Hermitian solutions to this system of operator equations for arbitrary operators without the closedness condition. Also, we study the Moore-Penrose inverse of a $n\times 1$ block operator matrix and then give the general form of common Hermitian solutions to this system of equations. Consequently, we give the necessary and sufficient conditions for the existence of common Hermitian solutions to the system of an operator equation and also present the necessary conditions for the solvability of the equation $\sum_{i=1}{n}T_iX_i=U$.https://ijnaa.semnan.ac.ir/article_4059_01638be695de3fa1c98b915e397bc3bf.pdf