You can put this solution on YOUR website! x-y=6 graph the equation
x-y=6
multiply both sides by -1
-x+y=-6
transpose x to other side
+y=-6+x
y=x-6
The points required are
x, y
3, -3
6, 0
9, 3
So plot the three points (3,-3), (6,0) & 9,3)and join them
You have the st line.
OK.