- Midpoint formula is
.
So starting with this one, we will be solving for the coordinates of the unknown endpoint separately. Starting with the x-coordinate, since we know that the midpoint x-coordinate is 5 and the x-coordinate of N is 2, our equation is set up as such: From here we can solve for the x-coordinate of Q.
Firstly, multiply both sides by 2:
Next, subtract both sides by 2 and your x-coordinate is
With finding the y-coordinate, it's a similar process as with the x-coordinate except that we are using the y-coordinates of the midpoint and endpoint N.
<u>Putting it together, the missing endpoint is (8,4).</u>
<em>(The process is pretty much the same with the other problems, so I'll go through them real quickly.)</em>
<h3>20.</h3><u>The missing endpoint is (7,2).</u>
<h3>21.</h3><u>The missing endpoint is (-5,1).</u>