SOLUTION: If (8, −9) is the midpoint of segment PQ and the coordinates of Q are (−3, −12), find the coordinates of P.

Algebra ->  Linear-equations -> SOLUTION: If (8, −9) is the midpoint of segment PQ and the coordinates of Q are (−3, −12), find the coordinates of P.      Log On


   

Question 1015150: If (8, −9)
is the midpoint of segment PQ and the coordinates of Q are
(−3, −12),
find the coordinates of P.
Found 2 solutions by Boreal, fractalier:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
The midpoint is an average of the x and y coordinates of each end
(-3+x)/2=8
-3+x=16
x=19
===============
(-12+y)/2=-9
-12+y=-18
y=-6
===============
(19,-6)
graph%28300%2C200%2C-10%2C20%2C-15%2C15%2C%283x%2F11%29-%28123%2F11%29%29

Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
You can kind of reason this out...the midpoint represents the average of the two endpoints, right?
Therefore the other endpoint is just as far in both x and y from the midpoint as is the first endpoint.
Q(-3, -12) ==> (8, -9) ==> P(19, -6)