size1=3
size2=3
A=
    6.13     -2.9     5.86 
    8.08    -6.31    -3.89 
   -4.36        1     0.19 
b=    6.23     5.37     2.29 
x=   -1.14    -2.83    0.851 
Ax=    6.23     5.37     2.29