An equation and two ordered pairs are given. Show that each pair is a solution. Then use the graph of the two points to determine another solution.

What I have so far:

y=x-5 (4, -1) and (1, -4)

for (4, -1):

4y=-1x-5

is the same as y=-1/4x-5

for (1,-4)

1y=-4x-5

is the same as y=1/-4x-5

I'm not entirely sure how I graph these, though. Could someone give me a hand?