 The variables corresponding to the columns of the identity matrix are called "basic variables" while the remaining variables are called "nonbasic" or "free variables".If the values of the nonbasic variables are set to 0, then the values of the basic variables are easily obtained as entries in "b" and this solution is a basic feasible solution.The algebraic interpretation here is that the coefficients of the linear equation represented by each row are either formula_26, formula_27, or some other number.