Answer:
A.

Negative reciprocal gives you the perpendicular slope so negative reciprocal of 1/2 is -2.
Then apply point-slope form.
B. The answer is x = 6.
The midpoint of JK is

The line that goes through JK is just a horizontal line
because the y-coordinate does not change. So its perpendicular bisector is the vertical line that goes through the x-coordinate of the midpoint, that is,
.