This chapter describes the numerical and symbolic solution of systems of linear equations. Systems where the number of unknowns is equal to the number of equations are considered as well as systems where there are more equations than unknowns (overdetermined systems) or fewer equations than unknowns (underdetermined systems). In all cases simple examples and graphical interpretations of the results are given. A unique way to solve the underdetermined systems found in statically indeterminate problems is discussed.