Question 139137
x+2y-1=0 
2y=-x+1
y=-x/2+1/2 (red line)
2x+y+1=0
y=-2x-1 (green line)
{{{ graph( 300, 200, -6, 5, -10, 10, -x/2 +1/2, -2x -1) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions -x/2 +1/2  and -2x -1). 
ANSWER (-1,1).