You can put this solution on YOUR website! 3X-5Y=7
-5Y=-3X+7
Y=-3X/-5+7/-5
Y=3X/5-7/5 (RED LINE)
-9X+15Y=-21
15Y=9X-21
Y=9X/15-21/15
Y=3X/5-7/5 (GREEN LINE)
THESE TWO EQUATIONS ARE IDENTICAL THEREFORE THERE IS NO UNIQUE SOLUTION. (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = 3x/5 - 7/5 and y = 3x/5 -7/5).