Question 1
A line segment on the coordinate plane has one endpoint at ; its midpoint is
. Which of the following gives the
-coordinate of its other endpoint in terms of
and
?
Explanation: To find the value of the
-coordinate of the other endpoint, we will assign the variable
. Then, since the
-coordinate of the midpoint of the segment is the mean of those of its endpoints, the equation that we can set up is
.
We solve for
:
