If the image of (-75,-65) in a line is (1, 2), then the equation of the line is
(3)
The required line is perpendicular bisector of the line segment joining the two points.
Equation of line joining (-75,-65) and (1,2) is
y-2x-1=-65-2-75-1⇒ 4x-3y+2=0
A line perpendicular to this line is 3x+4y+k=0 ...(i)
Also, line (i) passes through the midpoint of (-75,-65) and (1,2), i.e., (-15,25)
∴ 3(-15)+4(25)+k=0⇒ k=-1
So, the required line is 3x+4y-1=0