The image of the point (2, 4) in the line x+y-10=0 is
(3)
Let Q(α,β) be the image of point P(2,4) in the line x+y-10=0
The equation of line passing through P(2,4) and perpendicular to x+y-10=0 is (y-4)=1(x-2) i.e., -x+y-2=0
This meets with x+y-10=0 at (4,6),
Then, α+22=4, β+42=6 ⇒ α=6, β=8