Question 119769
x-y=-3 & x-y=4 do not have unique solutions:
x=y-3
(y-3)-y=4
y-3-y=4
-3=4 not a solution.
even if you attempt to graph these 2 equations there is no solution:
{{{ graph( 300, 200, -6, 5, -10, 10, y = x +3 , y = x -4) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = x +3 and y = x -4).