Question 314002
2x-y=1 
-Y=-2X+1
Y=2X-1 (RED LINE)
8x-4y=-8
-4Y=-8X-8
4Y=8X+8
Y=8X/4+8/4
Y=2X+2 (GREEN LINE)
{{{ graph( 300, 200, -6, 5, -10, 10, 2x -1, 2x +2) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions 2x =1 and 2x +2).
These two lines are parallel thus no intersection & no unique solution.