Question 121809
X+Y=3 OR Y=-X+3 (RED LINE)
X+Y=-1 OR Y=-X-1(GREEN LINE)
BECAUSE THESE 2 LINES DO NOT INTERSECT THERE IS NO UNIQUE SOLUTION.
{{{ graph( 300, 200, -6, 5, -10, 10, y = -x +3, y = -x -1) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = -x +3 and y = -x -1).