Since the first line has a slope of -4/7 and the other line has a slope of -1/7. This can be shown in point slope form y-y1=m(x-x1) where m=∆y/∆x.
Through points P and Q, the point slope is represented as -1-(-5)=m(-5-2) ; 4 = -7m ; m = 4/-7. The next two points R and S can be shown in point slope as 5-4=m(-2-5) ; 1 = -7m ; m =1/-7. With the fact that parallel lines must have equal slopes, these two lines cannot be parallel because -4/7≠-1/7
