Now use the Matlab backslash operator for the linear solve u

Now use the Matlab backslash operator for the linear solve (use format long to display 16 digits.)

Solution

Matlab code:

A=hilb(12);
B=A;
B(12,1)=B(12,1)+.00001;
b=rand(12,1)

x=A\\b;
y=B\\b;
norm(x-y)
% to identify the ill condition wrt solving the linear system
ans =
1.248179182526498e+012
ans/norm(x)
ans =
1.326285038669488