[1 2 3 | 4]
[2 4 6 | 8]
[12 9 6 | 3]

When I do rref(....) on my calculator, the answer is:

[1 0 -1 | -2]
[0 1 2 | 3]
[0 0 0 | 0]

I know that this means there are infintely many solutions for 'z' and I can solve for x and y from there.

Can you please show me how to do the math to get from the original augmented matrix to the one I get on my calculator. That is the bit I'm having trouble with.

Thanks!!

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