You can put this solution on YOUR website! You have equations with the 3 variables x, y, and z.
You want to write each equation in the form
and then you will use the coefficients A, B, C and D to build that matrix. <---> <---> <--->
So, --->
and your matrix could be
NOTE: There are other options, because each equation has an infinite number of equivalent equations, and you could rearrange your equations in different order.
For example, you could have used or as an equation equivalent to ,
and you could have used the coefficients of that equation for the top line of the matrix instead of the bottom line.