<PRE><B>Question 257344</B>
The centroid cuts the median into the proportions 2/3 and 1/3, but the ratio of the lengths is 2:1.
From your information, we have
x+6 = 2(2x-5)
solving for x, we get
x+6 = 4x - 10
16 = 3x
16/3 = x.
--
16/3 + 6 = 34/3 = AD
2*(16/3) - 5 = 17/3  = DM
Ad + DM = 34/3 + 17/3 = 51/3 = 17.</PRE>