Suppose that, #P(-3,7)# divide, in the ratio #lambda,# the join of
#A(-5,11) and B(4,-7)# from #A#.
Then, by the Section Formula, #P# must be,
#P((4lambda-5)/(lambda+1),(-7lambda+11)/(lambda+1))#.
Since, #P=P(-3,7),# we have,
#(4lambda-5)/(lambda+1)=-3, &, (-7lambda+11)/(lambda+1)=7#.
#:. 4lambda-5=-3lambda-3, &, -7lambda+11=7lambda+7#.
#:. 7lambda=2, and, -14lambda=-4#.
#:. lambda=2/7, and, lambda=(-4)/(-14)=2/7#, is the desired ratio.