You can put this solution on YOUR website! 3X-6Y=9, -6Y=-3X+9, Y=-3X/-6+9/-6, Y=X/2-3/2
X-2Y=3, -2Y=-X+3, Y=-X/-2+3/-2, Y=X/2-3/2
these 2 equations are the same therefore the 2 lines are the same. (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = x/2 -3/2 and y = x/2 -3/2).