% 
% Written by:
% -- 
% John L. Weatherwax                2007-07-01
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

clc;

% Solve each system one at a time: 
%
[ 3 1; -2 0 ] \ [ 5 ; 2 ] % x_1 = x_2 = 0 

[ -2 1; 1 0 ] \ [ 5 ; 2 ] % x_1 = x_3 = 0 

[ -2 3; 1 -2 ] \ [ 5 ; 2 ] % x_1 = x_4 = 0 

[ 1 1; 2 0 ] \ [ 5 ; 2 ] % x_2 = x_3 = 0 

[ 1 3; 2 -2 ] \ [ 5 ; 2 ] % x_2 = x_4 = 0 

[ 1 -2; 2 1 ] \ [ 5 ; 2 ] % x_3 = x_4 = 0 

% Evaluate the objective function at basic feasible solution: 
[ 0, 2, 0, 9; 1, 0, 0, 4; 2, 0, 1, 0 ] * [ -2; +3; -1; 0 ] % the true objective funtion 

[ 0, 2, 0, 9; 1, 0, 0, 4; 2, 0, 1, 0 ] * [ -2; -3; -1; 0 ] % the one with a typo