What are the x- and y- coordinates of point p on the directed line segment from a to b such that p is one-third the length of the line segment from a to b?

x = (startfraction m over m + n endfraction) (x 2 minus x 1) + x 1

y = (startfraction m over m + n endfraction) (y 2 minus y 1) + y 1

(1, 5)

(0, 3)
(–4, –5)
(–5, –7)