Question

Given the points A(-10, -4) and B(14, 4), find the coordinates of the point P on the directed line segment AB that partitions AB in the ratio 5:3.

Answer 1

P(5, 1)

Explanation:

Segment AB is to be partitioned in a ratio of 5:3. That means the ratio of the lengths of AP to PB is 5:3. We need to find the ratio of the lengths of AP to AB.

AP/PB = 5/3

By algebra:

PB/AP = 3/5

By a rule of proportions:

(PB + AP)/AP = (3 + 5)/5

PB + AP = AP + PB = AB

AB/AP = 8/5

AP/AB = 5/8

The first part of the segment is 5/8 of the length of the segment, and the second part of the segment has length of 3/8 of the length of segment AB.

Point P is located 5/8 of the distance from point A to point B. The x-coordinate of point P is 5/8 of the difference in x-coordinates added to the x-coordinate of point A. The y-coordinate of point P is 5/8 of the difference in y-coordinates added to the y-coordinate of point A.

x-coordinate:

difference in coordinates: |14 - (-10)| = |14 + 10| = 24

5/8 of 24 = 5/8 * 24 = 15

Add 15 to the x-coordinate of point A: -10 + 15 = 5

x-coordinate of point P: 5

y-coordinate:

difference in coordinates: |4 - (-4)| = |4 + 4| = 8

5/8 of 8 = 5/8 * 8 = 5

Add 5 to the y-coordinate of point A: -4 + 5 = 1

y-coordinate of point P: 1

Answer: P(5, 1)