Question

Find the coordinates of the other endpoint of the​ segment, given its midpoint and one endpoint.​ (Hint: Let​ (x,y) be the unknown endpoint. Apply the midpoint​ formula, and solve the two equations for x and​ y.)
Midpoint (-15,2) endpoint (-12,11)
What is the other endpoint?

Answer 1

Answer:

The other endpoint of the​ segment is $(-18,-7)$.

Step-by-step explanation:

The midpoint of the points $(x_1,y_1)$ and $(x_2,y_2)$ is given by the following formula:

                                          $(x_m,y_m)=(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2} )$

where $(x_m,y_m)$ = coordinates of the midpoint.

We know that the midpoint is (-15, 2) and an endpoint is (-12, 11). Substituting the information we have gives:

                                         $(-15,2)=(\frac{x_1-12}{2}, \frac{y_1+11}{2} )$

To find $x_1$ we need to solve this equation:

$-15=\frac{x_1-12}{2} \\\\\frac{x_1-12}{2}=-15\\\\\frac{2\left(x_1-12\right)}{2}=2\left(-15\right)\\\\x_1-12=-30\\\\x_1-12+12=-30+12\\\\x_1=-18$

and to find $y_1$ we need to solve this equation:

$2= \frac{y_1+11}{2} \\\\\frac{y_1+11}{2}=2\\\\\frac{2\left(y_1+11\right)}{2}=2\cdot \:2\\\\y_1+11=4\\\\y_1=-7$

The other endpoint of the​ segment is $(x_1,y_1)=(-18,-7)$.