How changes on coefficients affect the solution of the system

yiorgos

Hi,
Let the linear system Ax=b.
I am looking for literature describing how changes on coefficients matrix A affect the solution of the system x.
For example if the value of the (i,j) element is doubled how this will affect the solution x?
Are there standard techniques applying to any linear system?

EDIT: The A matrix is not known a priori and is quite large (thousands of equations), so techniques involving analytic solutions won't be of any help.