Question 714112
<pre>
There is no solution when the two shaded regions do not 
intersect. This occurs when the boundary lines are parallel 
and the  region between the boundary lines is not part of 
either shaded region.

An example is below.  

2y - x > 6
x - 2y > 8

The green region represents the solution to 2y - x > 6
The blue region represents the solution to x - 2y > 8.
There are no common solutions because the green and blue 
regions do not overlap anywhere.  

{{{drawing(400,400,-10,10,-10,10, graph(400,400,-10,10,-10,10,15,y>(1/2)x+3.1),
graph(400,400,-10,10,-10,10,-15,-18,-19,-20,-21,y<(1/2)x-4.1), graph(400,400,-10,10,-10,10,((1/2)x+3)*sqrt(sin(10x))/sqrt(sin(10x))),

graph(400,400,-10,10,-10,10,((1/2)x-4)*sqrt(sin(10x))/sqrt(sin(10x)))

 )}}}

Edwin</pre>