To find the slope of the line you must use the formula Y2 - Y1 / X2 - X1. It does not matter if you chose (4, 7) as X1 and Y1 or (1, 3) as X1 and Y1. For right now we will use (4, 7) as X1 and Y1, and (1, 3) as X2 and Y2.
Work:
3 - 7 = -4
1 - 4 = -3
-4 / -3 = 4/3
Answer: 4/3 (up 4, right 3)
(Since you are dividing by two negatives, the answer you will get will be positive)
I hope this helps!