Question 64177
Graph:
1) x-y = -3  Rewrite this as: y = x+3
2) x-y = 4  Rewrite this as: y = x-4

The graphs are:
{{{graph(300,200,-5,5,-5,5,x+3,x-4)}}}
As you can see, the lines are parallel, hence there is no solution because the lines do not intersect.