This program shows the solution in 3D of the 3x3 system of equations:

Plane 1: $x-y+z=-1$

Plane 2: $4x+y-2z=5$

Plane 3: $-3x-3y-4z=-16$

Which is the point in space located at: $$(1, 3, 1)$$ You can rotate by swiping with your finger or dragging with the mouse. You can zoom by pinching the screen or using the mousewheel. Pressing 'm' will make the window toggle fullscreen mode.

Note that the x-axis is green, the y-axis is red and the z-axis is blue.