Answer
y=-x+6
Work Step by Step
The line that describes all points equidistant from two two given coordinates, will have a slope that is opposite of the reciprocal of the slope between the coordinates and will pass through the midpoint between the coordinates.
slope=$\frac{5-2}{4-1}$
slope=1
opposite of reciprocal=-1
midpoint=($\frac{4+1}{2}$,$\frac{5+2}{2}$)
midpoint=(2.5,3.5)
y=mx+b
y=(-1)x+b
3.5=-1(2.5)+b
b=6
y=mx+b
y=-x+6