Hi Adrianna W.
P(5,4)
Just for clarity, I have a question, you want to know the coordinates of point P on the directed line segment AB based the ratio of the distances of A to P and P to B?
(AP)/(PB) = 3/1?
Where AP = The coordinates of P minus the coordinates of A.
x -(-4)
y-7
Where PB = The coordinates of B minus the coordinates of P
8-x
3-y
If so, then according to the ratio just plug in the values and solve for
The x coordinate
AP = 3(PB)
x + 4 = 3(8-x)
x+4 = 24 - 3x
x + 3x = 24 -4
4x = 20
x = 5
The y coordinate is calculated the same way
y-7 = 3(3-y)
y-7 = 9 -3y
y + 3y = 9 + 7
4y = 16
y = 4
The coordinates of P = (5,4)
Checking the ratio of the distances AP/PB
(5-(-4))/(8-5) = (5+4)/(3)= 9/3 = 3/1
You can check the ratio of the y distance in the same manner
While there are several other ways to do the problem if the question I asked above is true I hope this helps.