Question

why the solution set of parallel lines are not possible

Answer 1

It is so because parallel lines never intersect so they never have a solution till infinity they remain parallel
Hope it helps

Answer 2

parallel lines never cross ..it has infinite number of solution it is dependent.. when u graph the equation both equation represent at the same line ... if system.has no solution it said to be inconsistent...
in consistent means --not compatible or not staying in the same throughout...
the graph of lines never intersect so they are parallel and there is no solution....
hope its help u