SOLUTION: the midpoint of "AB" is M. If the coordinates of A are (2,-6) and the coordinates of M are (5,-1) what are the coordinates of B?

Algebra ->  Length-and-distance -> SOLUTION: the midpoint of "AB" is M. If the coordinates of A are (2,-6) and the coordinates of M are (5,-1) what are the coordinates of B?      Log On


   



Question 697381: the midpoint of "AB" is M. If the coordinates of A are (2,-6) and the coordinates of M are (5,-1) what are the coordinates of B?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
You are looking for B( x,y ) which is
an endpoint.
The x-coordinate of the mid-point is
defined as:
(1) +%28+x%5BA%5D+%2B+x%5BB%5D+%29+%2F+2+=+x%5BM%5D+
The y-coordinate of the mid-point is
defined as:
(2) +%28+y%5BA%5D+%2B+y%5BB%5D+%29+%2F+2+=+y%5BM%5D+
-------------------------
+x%5BA%5D+=+2+
+y%5BA%5D+=+-6+
+x%5BM%5D+=+5+
+y%5BM%5D+=+-1+
-------------
Filling in the numbers:
(1) +%28+2+%2B+x%5BB%5D+%29+%2F+2+=+5+
(2) +%28+-6+%2B+y%5BB%5D+%29+%2F+2+=+-1+
-------------------------
(1) +2+%2B+x%5BB%5D+=+10+
(1) +x%5BB%5D+=+8+
and
(2) +-6+%2B+y%5BB%5D+=+-2+
(2) +y%5BB%5D+=+4+
----------------
The coordinates of B are: B( 8,4 )