Solving Augmented Matrices with Gaussian Method

[kash-k]

|1 -5 2 |-5
|3 -14 3 |-8
|4 -18 8 |-8

above is a augmented matrix of a 3 equations. now i know that you can solve these via simul. equations however, my textbook solves them via some gaussian method but doesn't mention how it's done. it just shows -

1 -5 2 |-5
0 1 -3 |7
0 0 1 |-2

how does the textbook go from augment 1 to augment 2 using this guassian method?

thanks in advance :)

 

[Defennder]

You can find an explanation and an example of how the Gaussian elimination works here:
http://en.wikipedia.org/wiki/Gaussian_elimination

 

[kash-k]

did you read it?
because i read it before i posted and let me tell you it's not helpful.

 

[Defennder]

Why isn't it helpful? Did you try following the example? It seems ok to me. So it goes like this:
You multiply the first row by a constant such that when it is added to the 2nd row, the left most number of the second row becomes 0. Do that to the 3rd row, then use the second row as a reference to reduce the 3rd row.