gauss jordan pivot in javascript simplex method

Question

I have read and analyzed the source code here for my problem:

I find it difficult to pivot this 5x8 matrix which is contained in a 2D array. Can someone help and explain the steps on this? Different sources show different solutions. But the cited link above is the output I want to achieve. Codes are pretty appreciated :)

BTW, I am making a simplex method in pure javascript.

Answer 1

better read than the forementioned link The Simplex Method: Solving Standard Maximization Problems