If someone could please help me with this. its a question about Solving a system using elementary row operations which is honestly one of the easiest and msot simple things to do but for the life of me I cannt understand what I am doing wrong

I solved the system so i know what hte answers are but when doing elementary row operations method i keep getting wrong answers

the Matrix is as per below

3 -2 1 2

1 -1 -1 -4

4 1 -2 0

please if someone could could..just really frustrated at this point