Find k given that the point (2 k)is equidistant from (3 7) and (9 11)

Answer 1

just use your distance formula:
(3-2)^2 + (7-k)^2 = (9-2)^2 + (11-k)^2
k = 15

or, note that the line through (3,7) and (9,11) is
y = 2/3 x + 5
The perpendicular bisector of that segment is
y = -3/2 x + 18
when x=2, y=15