write an equation in general form...

Question

the perpendicular bisector of the segment with endpoints at (2,-1) and (4,-5). I found the slope and then found the mid point and wrote to the equation and got X-2Y=3. But the answer is X-2Y=9...any help???

Answer 1

slope is of the segment is -2, you got that correct, and slope of bisector is 1/2, right. The midpoint is at 3,-3

y=mx+b
-3=3/2 + b
b= -4.5

y=1/2 x -4.5
2y=x-9
x-2y=9

Answer 2

The mid point of the segment is
((x1+x2)/2, (y1+y2)/2)=(3,-3)
You have correctly calculated the slope m as 1/2.
Using the equation
(y-y1)=m(x-x1),
we get
(y-(-3))=(1/2)(x-3)
2(y+3)=x-3
x-2y=9
You have probably mis-calculated the mid-point as (-3,-3)