Question 89286
2y-y=4 or y=4 (red line)
2y-y=6 or y=6 (green line)
{{{ graph( 300, 200, -6, 5, -10, 10, y = 4, y = 6) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = 4 and y = 6). 
---------------------------------------------------------------------
x-2y=8 or -2y=-x+8 or y=-x/-2+8/-2 or y=x/2-4 (red line)
3x-2y=12 or -2y=-3x+12 or y=-3x/-2+12/-2 or y=3x/2-6 (green line)
{{{ graph( 300, 200, -6, 5, -10, 10, y = x/2 -4, y = 3x/2 -6) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = x/2 -4 and y = 3x/2 -6).