Introduction to Linear Algebra, Gilbert Strang, 2016 (Wellesley-Cambridge Press) - A standard textbook that explains fundamental concepts of linear equations, matrix inversion, and the theoretical solution $x = A^{-1}b$.
Numerical Linear Algebra, Lloyd N. Trefethen and David Bau III, 1997 (Society for Industrial and Applied Mathematics (SIAM))DOI: 10.1137/1.9781611971276 - Provides a rigorous treatment of numerical methods for solving linear systems, discussing the efficiency and stability of approaches like Gaussian elimination compared to explicit matrix inversion.
Linear Algebra (18.06), Gilbert Strang, 2010 (Massachusetts Institute of Technology (MIT) OpenCourseWare) - Offers video lectures and course materials that complement textbook explanations of systems of equations and matrix inverses, available freely online.