Answer :
distance formula : sqrt (x2 - x1)^2 + (y2 - y1)^2
(-1,5)....x1 = -1 and y1 = 5
(4,1)...x2 = 4 and y2 = 1
now we sub and solve
d = sqrt ((4 - (-1)^2 + (1 - 5)^2)
d = sqrt ((5^2 + (-4^2))
d = sqrt (25 + 16)
d = sqrt 41
d = 6.4 <=== ur distance
(-1,5)....x1 = -1 and y1 = 5
(4,1)...x2 = 4 and y2 = 1
now we sub and solve
d = sqrt ((4 - (-1)^2 + (1 - 5)^2)
d = sqrt ((5^2 + (-4^2))
d = sqrt (25 + 16)
d = sqrt 41
d = 6.4 <=== ur distance