How to LU facctorisation of a 4 by 4 matrice using gaussian eilimination! I have a 4 by 4 matrice,
A = [2 -2 0 0]
    [2 -4 2 0]
    [0 -2 4 -2]
    [0 0 2 -4]
How would I use Gaussian Elimination to find the LU factorisation of the matrix
Please could someone explain how to do this!? I have an exam where a similar question will come up so i really want to be able to fully understand this. I can do and completely understand Gaussian elimination of a 3 by 3 matrix but not when it is not a system on equations! I havnt seen anything like this before!
Many thanks

Hint: In general, we premultiply matrix $A$ to get upper traiangular matrix $U$,i.e $$ (HGFE)A = U $$
then $$A=(HGFE)^{-1}U$$
$$A = E^{-1}F^{-1}G^{-1}H^{-1}U$$
$$A=LU$$ where $L = E^{-1}F^{-1}G^{-1}H^{-1}$
