% Example 7
% lagrange multiplier –
% example
A= [2  0  0 -1 -2;
    0  2  0 -2 -2;
    0  0  2 -3 -1;
    1  2  3  0  0;
    2  2  1  0  0];
 b=[0; 0; 0; 7; 4.5];
 x = A\b