My solution showed
how do I go about putting this on a graph?
The system of equations represents the intersection of three planes. The three planes intersect at the point (x,y,z) = (1,4,-2). To graph this, you should attempt to graph the three individual planes and show that they intersect at the point you calculated. 3-d rendering is not a strong suit of mine and I don't have a great way to send you drawings. So I will describe the procedure.
First draw the three axes x,y,z. ...
Solution explains in step-by-step detail how to graph the solution to a matrix solved by Gaussian elimination.