[b]Try this question just using the inverse matrix function on your calculator then check it using the 3D GeoGebra app below.[/b][br][br][br]
What are the coordinates of the point of intersection of the planes:[br][b]5x-y+2z=5[/b][br][b]x-5y-2z=-11[/b][br][b]x+y+2z=3[/b]