Let the line p be the perpendicular bisector of A = (24, 7) and B = (-3, 4). Given that AB meets p at C = (x, y), what is 2x - 4y.
The midpoint of AB will be C = [ ( 24 -3)/2 , (7 + 4) /2 ] = (21/2 , 11/2)
So
2(21/2) - 4(11/2) =
21 - 22 =
-1
