Question 231939
x-y=6
x=y+2
(y+2)-y=6
y+2-y=6
0=6-4 
0=2 no solution.
Proof:
x-y=6
-y=-x+6
y=x-6 (red line)
x=y+2
y=x-2 (green line)
{{{ graph( 300, 200, -6, 5, -10, 10, x -6, x -2) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions x -6 and x -2).