Midpoint of a Segment

Example on how to use the midpoint to find point of segment.

Example 1

$A(-3,6)$ and $B(x,10)$ are points on a standard plane. Find $x$ so that point $M(3,8)$ is the midpoint of segment $AB$.
  1. $-3$
  2. $3$
  3. $6$
  4. $9$
  5. $1$

Solution

This example is about finding a point of a segment given the second point of the segment and it midpoint.

  1. Use the formula for the midpoint of a segment $AB$

    $(3,8)=(\dfrac{-3+x}{2},\dfrac{6+10}{2})$

  2. Using the above, we can write that the

    $3=\dfrac{-3+x}{2}$

  3. Solve for $x$

    $-3+x=6$

    $x = 9$

    Answer D