Firstly, we will draw diagram of the scenario
Dana reflects point A(2,5) across line small script letter lℓ to get image point Upper A primeA′(6,1)
It means that AA' is perpendicular bisects of line(l)
so, let's assume it intersects at point M
so, M will be mid-point between A and A'
M is a point on line (l)
now, we will find slope of line on AA'
x1=2 , y1=5
x2=6 , y2=1
now, we can plug values
now, we know that line (l) and AA' are perpendicular to each other
so, slope of line(l) is -1/m
slope=1
so, we have slope and a point
now, we can use point slope form of line
now, we can plug values
so, the equation of line (l) is
..............Answer